I've never experienced any game stability problems with BG2. Why not try one of the 'official' resolutions (say, 800 x 600) and see if the problems go away?
If it doesn't at least you know it's not the higher resolution that is causing the crash.
My screen resolution is 1024 x 768, but I play BG2 at 800 x 600.
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"Butt-kicking for goodness!" - Minsc
"Cities always teem with evil and decay. Let's give it a good shake and SEE WHAT FALLS OUT!!" - Minsc
