Uh, I'm not a developer or anything, but maybe your video card/screen doesn't supports 1024x768@32 ?
Try changing the values in the file glest.ini from
ScreenHeight=768
ScreenWidth=1024
to
ScreenHeight=800
ScreenWidth=600
or
ScreenHeight=640
ScreenWidth=480
and also
ColorBits=32
to
ColorBits=16
or
ColorBits=8
thought I dunno if ColorBits=8 will work.