Blender animation keeps crashing

I am currently working on a very complex animation.

When I press ctrl-a after editing some ipo curves, blender often freezes, then crashes. I am not running any background programs, and I don’t think it’s a problem with my system (I have 768 Ram, 2.0 Ghz processor)

Maybe because I am running the blender sequencer? although that is only sounds, and they are muted. It only freezes half of the time.

Does anyone else have this problem?