No, have not had that problem, though I am running 2010 Pro.  But before I upgraded I did not have that problem  I have rendered as many as 7,000 frames, though usually they stay around 2000 to 4000.   There was an update SP3 to eight just a few days ago, did you download that one?  Were you having problems before you updated it?

Also have you checked the box to use 64 bit rendering, that is if your system is a 64 bit system 

the possibility that your graphic's driver may not be up to date.  Check and see.