My girlfriend's computer has been acting very strange lately. The first thing that poked its head up was that the google search in firefox wouldn't work. You could type in it but pressing enter did nothing. Next, the go back and foward a page buttons stopped working. Then Microsoft Word couldn't save anything, every so often accompanied by the startup disk is full message when we still have over 100 GB left. After restart, these problems would go away. This wasn't too much of a bother until these sorts of problems started happening daily, then every 8 hours or so, then every 1-3 hours. We took it to the Genius bar at a peak of one of its death spirals and of course the first thing they did was restart it. We would not be at the apple store long enough to wait for the computer to bug out again, so they offered to take it in for some stress testing. We picked it up a week later with 18 hours of passed stress testing under its belt (i have the results if you need it). The Mac guys told us to make a backup if we hadn't already (we hadn't) and if the problem happened again, we could come in and they would reinstall Mac OSX. We were pretty surprised that no problems were found but took it home anyways hoping for the best. Of course, after running Word on it for less than an hour, it wouldn't allow us to save again. We restarted and tried to make a backup, but the computer crashed before we were half done even formatting the external hard drive. We took it back into the Mac store and they reinstalled Mac OSX on it and while there we dragged the backup back onto the computer (of course nothing goes wrong at the Mac store). We go home and when we start to install Word, it doesn't let us. The second time, it freezes halfway through. At this point we've pretty much given up on trying to solve it ourselves. We make another appointment and there they installed Word for us and Firefox. We were told to do what we normally do on the computer until the problem arrises again. We do so and the Mac guy tells us that our problem is we don't have enough RAM. He said, "Somehow, your habits have changed so that you use more memory." I was very sure this is not the problem, but I had nothing to prove it (and i think he was getting annoyed of us being there, 3 times in 2 days ). He had Activity Monitor open showing how we had no free memory left. We left with the advice of buying more memory. (update on problems: all the function keys except for the dashboard key did not work, trying to empty trash or move something to trash resulted in Error Code-50, saving/moving files around was unsuccessful) Back home, we booted up the computer once more to record some of the things that happened to make sure this was the issue before buying more RAM and having to put it in ourselves :/ (remember these things are happening at increasing rates with more problems showing up almost every time) We noticed that 1. Firefox would not open and would give the message, "Another copy of Firefox is open". Checking the Activity Monitor, we saw no Firefox (only when we tried to open one did a Firefox appear in the Activity Monitor). 2. Told us to install word as if it had not been installed yet. (back to normal on restart) 2. (this is right after restart) clicking on the Microsoft Office applications on the launch bar only resulted in them hopping once; no startup. only outlook tried to run (as we can tell from the Activity Monity) only to become non-responsive. Also, Most of the applications on the launch bar would not work and could not save (they looked liked they saved but when reopened, nothing had been changed) 3. The computer was very slow at simple tasks like switching the desktop picture (still had 500MB free memory, 6MB of swap) 4. Surprised we just noticed it then. The Desktop icons were missing 5. Stuck on logout. with that launch bar thing still open on the bottom but no finder menubar on top. (could still open system preferences and activity monitor which would bring the top menu bar back) 6. force quit doesn't work, finder does not open. (when stuck on logout) 7. Every so often right after restart an error message shows up with a power symbol on it telling us to restart the computer. 8. Quick Look Helper often times would take about 200% of CPU and would hardly ever go down unless we quit the process Hm.. that's all i can think of now. I downloaded memtest and ran it a couple times. One time an error showed up. I think it said "SB 1 SS 0 SA 1" but i don't remember as the computer ran out of battery by then : P I ran it a second time and it worked fine, although 2 tests took 3110 seconds. Anybody got any ideas? Is it that we "have changed our habits and are now using more memory"? Any help will be very much appreciated. oh ya, in case this has anything to do with it, we had taken the computer in twice before because the hard drive could not be found. They replaced the hard drive cable both times because it was loose.