First off, I think this is (could be) a great game. Before I go further, let me say that I'm playing Twilight on a machine that easily exceeds the requirements of the game. 2.4 Ghz dual-core, 4 Gb RAM, running Vista
1. I have yet to finish a game without it crashing. Its been crashing in 2 ways: (1) if I play for an extended amount of time, like 5 or 6 hours straight, then it gets an out of memory error during one of the autosaves. Sounds like a memory leak to me. (2) sometimes the survey ships seem to get stuck making a routing decision and they sit there and toggle back and forth with a clicking sound. When this happens, the "Turn" button is disabled and it never gets reenabled. End up having to end the game in task manager and start over from last save.
2. Once in awhile for no apparent reason, I can't get the game to load saved games. No idea what the problem here is. I keep retrying and eventually it works.