I didn't read all the posts here but I had the same problem, I found that runing EQ2 in SLI (crossfire) mode case this too happen on my system. Geforce 260's I disable SLI (crossfire) and it works fine. Hope you found a fix.

so this thread has been necroed for the third time now? really? appreciate the helpfulness guys but the OP is probably dead by now, this thread is from 2005. :p