FATAL ERROR with prime95

i have overclocked my amd athlon 64 x2 5200+ from 2.7 to 3.0 and i was stressing it with prime95 , at the first test (1024k) i got this error "FATAL ERROR : Rounding was 0.5 ,expected less than 0.4" (thats for the 2nd core)
Any ideas what that means ,and what went wrong ? i got the error yesterday and i havent turn the pc off from then .. i was playing games (saints row the third , gta 4) , watching movies ( full hd) and everything is still ok (the temp stays at 75 C when stressed, 18 C when browsing at internet only)

so no 1 can tell me what is this error and how can i fix it ?

so if i rise the vcore it will be ok ( i had puted it on 1.47 before and everything was ok except the temp wich was 95-96 C) now its 2.9 ghz at 1.38 cause its fully stable.
i can put the vcore at default (1.33) , +3.3% (1.38) ,+6.6% (1.42) and +10% (1.47)
i have tried to put it on 3.0 ghz and 1.42 but it failed the stress after 3 mins (before was after 50 sec). how to lower the bandwith?

First you probably can not over clock the cpu by very much with the stock cooler. Here is a link to the forums OC guide (http://www.tomshardware.com/forum/258573-29-black-edition-overclock-guide-raising-multiplier). This link may also help you (http://www.overclockers.com/forums/showthread.php?t=671558). Each sample is a bit different so it is a trial and error sort of thing to get a stable OC. Bandwidth is what you are calling the CPU speed. To get further help in the forum, I suggest you close this thread and open a new one "Help to OC athlon 64 x2 5200+". I am more familiar with Intel OC and the new thread will get AMD pro's to help you.