Strange graphic problem.

[Lari]

I have a x1650pro , xp x64, and 2Gb Ram. Everything updated to last week. I have graphical problem similar to this one in long battles. Everything runs fine till round 20 maybe a little more, then the hex grid start to disappear, charges from lina becomes invisible or blur/blink, and even worst after that. By turn 50 it is almost unplayable. If i win the battle and go to the next one everything go back to normal. Think maybe is a problem with the 1600 series

Playing 1.6.5 at 1280x1024