I took the plunge on one of these to replace my ancient 11.b gear.  I wanted to do some IP net cameras and VOIP and got tired of waiting for the final 11.n standard.  Maybe I should have waited??  
 
The gear seemed to work pretty well (and fast!) for awhile.   I live in a townhouse environment with several other 11.g networks visible and I  tried several channels until I got the best performance.  Link connection speeds consistently came in at 243 or 300 Mbps (I know not actual real world speeds, but very good nonetheless.)  The only issue I had was that during activity like transferring a lagre file to my NAS the reported link speed would drop somewhere between half of the above numbers and the original number.  The link speed would return to the full value immediately upon completion or cancellation of the activity.
 
Now lately the connection seems to have become really unstable.  The reported link speed on my laptop and desktop with the corresponding D-link wireless adapters fluctuates and I get numerous network disconnections.  Not sure if there is some change in the environment like new networks (no more are visible than before) or some problem with the gear.
 
Oh, one other issue I have discovered is that I cannot connect to an 802.11g Axis wireless IP camera with the DIR-655 in mixed ng, g, and b mode.  I have to set it to pure 11.g mode to establish connectivity to that device.  Sort of defeats the purpose.  I could have done just as well with an 11.g unit for half the price.
 
I'm not sure if I have the patience to wade through the D-link (non) terchnical support system to try to fix these issues.

Run Netstumbler and see if you have a new network. The 11n spec requires the 11n to dropout of 11n bonding, which means 11g fall back. So if a network (maybe your camera) is forcing your connection down.

Netstumbler reports the same nets I see on the D-Link utility.  I am on channel 1 and the other 2 are on 6 and 10.
 
I am running in pure 11g mode (so I can actually use the camera) and I am still getting the fluctuations and dropouts.  Interesting that I get a more stable connection when I hop over and log onto my neighbors open 11g linksys router.

It is all very strange.  Just sitting here watching the D-Link utility....  set on pure 802.11g with 95%-100% signal strength connection speed goes from 54 to zero, network reports off line, then back uop to 54 Mbps all in the pace of 10-15 seconds.  Over and over although it does seem to settle down now and then for a couple of minutes.  This is getting real old....  I have to try to submit this during a time when I am actually connected.  :-/

Do you have any cordless phone around? They can wreck havic on a 2.4ghz network.  
 
If you have Netstumbler loaded on your NB, check you strength. Move around and see how it changes. Some radio sensitivities vary, Some handle low signal better than others. I have a raylink min-pci card in my NB. It is junk, will not stay connect 10 feet from the AP on High. With my pcmci card I can cover my whole house on low power.  
 
Not all radios are equal. Make sure you have all of the latest drivers installed.

I understand about the 2.4 phones.  If there is one it isn't mine but no way to be sure if another nearby townhouse doesn't have one.  It's a gd bet thattheer are several around.
 
As to my radios... I have the latest D-Link Extreme N NB and DT adapters that match the router.  And the other funny thing is when it goes unstable it even affects a wired ethernet connection.  I have disabled the desktop adapter and jacked in with a a cat5 cable and had the same issues.   Right now everything is rock solid steady.  Go figure....  Question.. is it possible that 2.4 GHz phone interference could destabilize a router even to the point of affecting the wired ethernet switch?

And as soon as I  submitted the last post my network started it's roller coaster changes in connex speed and connectivity.

And as soon as I  submitted the last post my network started it's roller coaster changes in connex speed and connectivity.

I think all of your problem is the pre 11n firmware. There has been complaints throughout.  I think the netgear has been the least of problems, but still has them. Dell is instructing users who opted for the pre11n to set it to 11g only. Disabling the 11n function.  
 
This is the price you pay for being a beta tester after you paid a premium for the hardware. I think yours may be a hardware problem. RMA your router. Hopefully you may get one that meets the v2 spec.

Yeah, I knew there were issues with the draft stuff.  But I thought they might be getting closer and I couldn't live with b anymore.  I guess I should have bought a cheap reliable g router for the interim.
 
I reflashed the firmware and reset to factory defaults to see if that will help.  I didn't have too many custom settings.  I saved the configuration but I think I'll try adding them back one by one to see if I can isolate a problem.  
 
BTW, I am having an issue with another piece of D-Link gear a wired ethernet camera/server.  The buttons and tabs on two of the most critical setup pages in the web interface don't function when I run the interface from either of my computers on my LAN.  But when I connect through the virtual server port from an outside computer it works great.  No unusual security setting on my machines and every other page works fine ... Another baffler....
 
BTW, since I reflashed the router is is stable on the wired connection.  Gonna bring up the wireless in a few minutes.  This is getting old!

If the hardware works with the v2 spec it is closer, but your still 9-12mo off before finalization.
 
I can relate to being a beta tester, was one for my router. But I was getting anywhere from 2-3 per week. I had to reset everything back to factory before installing any updates. I had a list of things I did/tested with every release. One took 4 days to know if it was working.
 
Good luck

Here is a Network Magic log printout for about a half hour from my notebook last night.  The log from the wired desktop reported it coming on and off the net the same as the wireless notebook.
 
Axis270W left the network 7:09 PM
Toshiba Notebook joined the network 7:09 PM
Toshiba Notebook left the network 7:09 PM
Axis270W joined the network 7:06 PM
Toshiba Notebook joined the network 7:06 PM
Toshiba Notebook left the network 7:06 PM
Toshiba Notebook joined the network 7:03 PM
Toshiba Notebook left the network 7:03 PM
Toshiba Notebook joined the network 7:00 PM
Toshiba Notebook left the network 7:00 PM
Toshiba Notebook joined the network 6:58 PM
Toshiba Notebook left the network 6:58 PM
Toshiba Notebook joined the network 6:55 PM
Toshiba Notebook left the network 6:55 PM
Toshiba Notebook joined the network 6:52 PM
Toshiba Notebook left the network 6:52 PM
Toshiba Notebook joined the network 6:49 PM
Toshiba Notebook left the network 6:49 PM
Toshiba Notebook joined the network 6:47 PM
Toshiba Notebook left the network 6:47 PM
Toshiba Notebook joined the network 6:44 PM
Toshiba Notebook left the network 6:44 PM
Toshiba Notebook joined the network 6:43 PM
Toshiba Notebook left the network 6:43 PM
Toshiba Notebook joined the network 6:43 PM
Toshiba Notebook left the network 6:43 PM
Toshiba Notebook joined the network 6:34 PM
Toshiba Notebook left the network 6:34 PM
Axis270W left the network 6:34 PM
Toshiba Notebook joined the network 6:34 PM
Toshiba Notebook left the network 6:33 PM
 
So... I gave up on this router and reinstalled my old Siemens 11b unit.  All the gear (1 wired PC, 1 wireless notebook, 1 wired ip cam, one 11g wireless ip cam, NAS) works and the network is stable... but way too slow to allow me to take the desktop wireless and relocate my office.
 
Took the D-link stuff back to Best Buy and got a Linksys WRT54g setup for less than half the price.  Maybe not as fast for transferring DVD video files but at least it is standards based and will hopefully be stable.  I never had any stability issues when I logged onto my neighbors open WRT54g.
 
I'll leave the 11n beta testing to others and wait for the real thing if/when it ever becomes reality.

D-link has a bunch of issues more recently.
 
One is the 40mhz issue and rate changing between n and g standards, as in the router does not do it correctly.
 
Some other issues you amy be dealing with are channel overlap from you neighbors, and or chipset incompatibilities.
 
Additionall D-links newest screw up includes that their newest network cards only work properly if you are operating the computer LOGGED IN under a administrator account!
 
The only (2) D-Link routers I can recommend currently are the DI-634M and the DGL4300 either out fo the box or with updated firmware.
Both use the same CPU and similar programming....one has MIMO and a default broader encompassing QOS the other has more specific gaming QOS and gigabit ports.
 
The matching wireless D-link cards are the DWL-G520M and the DWL-G520
 
 
I can also recommend Netgear's WPNT834 out of the box  
or
Linksys's Linksys WRT54GL with alternative firmware.
 
 
For a system more designed for security I would suggest the Hotbrick SoHo 401W with the current manufactuer's firmware.  The intrusion detection on this unit is Unreal.
 
 
These recommendations are based on ease of use after being set up and or having fewer bugs then most other products available.  
 
I currently run the DI-834M as my primary gateway and nat router. I also have a hotbrick 401 VPN placed in the DMZ zone of the DI-834M
My server has one ethernet port attached to the Hotbrick and a second ethernet port attached to my intranet.  My intranet is a GS108 netgear gigabit switch uplinked into the DI-634M
 
My internal network runs all gigabit speeds with jumbo frames.
 
I can drive 128+ concurrent connections using file sharing without bogging down my routers.  The QOS services on the DI-834M enable computers on my network to browse at near full speed while I am doing P2P or gaming.  I have other layers of security on my system, but thats not part of what I am trying to explain.
 
I am using a few quality parts each good at what they do to give me the best that I can have given my requirements.
 
The DIR-855 has the possiblity of being the replacement for the switch and the DI-634M but not until they fix the firmware.

Hello all,
 
 I have a question about an issue with the Dir 655 I could use some help with.
 
On my home network (up and running for 3 years)Replacing the linksys router with the Dlink dir-655 router I  
cannot see any wired devices on my home network with my second Laptop running Vista home premium.
My first laptop with Home basic and all wired devices work fine and can even see the 1st Laptop.  
 
I do see other wireless devices and the Media ports of both NAS drives on the second laptop.
 
Putting the Linksys router back,(even without resetting anything) fixes the problem.
 
I have tried resetting up the DIR655 twice following the step by step provided and then turning  
off all security to no avail.
 
I believe there must be a "home premium" conflict somewhere but I cannot find it.
 any ideas?
 
I would like to eventually setup my home network as a media server using the Dlink DSM-750
 
My previous network set was a follows:
Linksys WRT54gs router
1st Desktop running XP professional
2nd Desktop running XP home edition
1st Laptop runing Vista home basic
2nd Laptop running Vista home premium
Dlink DNS-323 NAS - 1 750Gbyte drive
Airlink anas-350 NAS - 1 500 Gbyte drive.
 
Steven