A few months back I was having problems with my cursor disappearing and was told that it was probably the USB on my cinema displays causing it. So I stopped using the cinema display usb/firewire hubs and also removed 2 512MB sticks of Kingston value RAM in case it was related to that. I was working on a motion project today that wouldn't run without more RAM so I reinstalled, and low and behold my cursor is disappearing again. When it disappears, it's not just invisible, it actually just ceases to exist - moving the mouse around and clicking does nothing. If I restart the Finder that never helps either. I checked the RAM with Techtoo and it checked out okay. Has anyone else experienced this?