Just wondering if anyone has worked with an iMovie document off of a USB 2.0 External HD. I'm currently trying to trade mine for a FW400 HD, but may decide to keep it if it's fast enough. I ask because I work on many very important documents and don't want to find out half way through that it messed up my document due to speed issues. Not just working on the document off the drive, but importing video into it as well. Thanks.