this is a problem that i have since a lot of builds. when recompiling a lot of classes, idea parses them, compiles them, updates its caches and locks up. grey screen, almost no cpu usage, and according to the winXP task manager, very little but constant i/o writes and "other", whatever that means.
it's not a dead lock because the operation always finishes, but it may take up to 15 minutes.
what could be the cause? i've never experienced this problem at home (max classes ~3k), but at work i have to wait ~15 minutes when 3k classes of our 12k have changed. (cpu is a 3ghz p4, 2gb ram)