Haven't seen this on any forums. But I've noticed that Keylight in CS5 has tremendous memory leaks. If you do purely Keylight work for a couple of days, After Effects will just keep on eating up the RAM. Quitting out of AE doesn't solve the problem nor does clearing the cache. On a 12-core Mac Pro with 32GB of RAM, Keylight will cause AE to consume 24GB of RAM of a few hours of work. The only way to clear the memory is a reboot.