I am having problems importing and exporting video. When I import, after several minutes, it stops. When exporting to video or tape, the video freezes. I'm using FCP4, and work on a 1.6 GHz Power PC G5. Memory 1.5 GB DDR SDRAM. I do get the spinning circle quite oftern. This did not happen when I first bought machine(used). Do I need more RAM? Help? I need to get this stuff finished!