I've been having problems recently where files seem to become damaged for no apparent reason. For example, I had a video file which played fine, then tried it again a couple of days later and found that some of the frames were damaged. I've also had BitTorrent downloads fail due to detected corruption, the BT client asks me to ensure that no other apps are accessing the file at the same time. In addition, apps sometimes quit without warning (Word quit itself before, when I wasn't even touching the computer). I've tried the usual things like repairing permissions, and I have a suspicion that it's bad memory, but Apple Hardware Test didn't find anything wrong with it (it's Samsung memory, the same stuff Apple uses). Any suggestions? I might remove some memory and see whether it helps.