I've noticed a couple of little details that might help someone having mysterious ctd running DA ...
My anti-virus doesn't like the dwwin.exe starting a new process. For some reason, for instance when I clik turn, a new process is started (sometimes, not every time) by dwwin.exe ... the only ctd I get is not from the cpu or the system, but from the anti-virus blocking the new process being started, because it's a suspicious behavior.
With GCIIDA on fullscreen, the "blocked such and such" pop-ups are not visible, so I didn't have a clue. It was only when I dropped DA to a window that I could see them. Same for the firewall pop-ups when trying to post to the Metaverse. You may want to try DA in a window, see if any pop-ups have been hiding behind fullscreen.
Graphics are a little jerky sometimes, but no big slowdowns. GCIIDA 1.59[b].098, WinXP without the hotfix,AMD 6000+ cpu (with the timer update and the Cool&Quiet update), crosshair mobo, nvidia7950gt - works great, no probs except that mentioned above, even on gigantic maps.
P.S. - the way to get GCIIDa into a "window" is to go in the game and change the screen size under 'esc>>options>>video', then restart the game.