If you post the debug.err file found in your galciv2 folder (C:\Program Files\Stardock\TotalGaming\GalCiv 2\ or C:\Program Files\Stardock\GalCiv 2\ by default) it can help the devs to figure out your problem.
Also, download SmartException from the 'Free Stuff' section in SDC, and run it while you play GC2. Then when it crashes SE will gather some information about the crash. You can then do a search in windows explorer for a file named galciv2.exe.cra, this file will contain SE's report which you should also post.