Firewire problems and how to avoid them.
 

If you go to Tim Dashwood's "Sticky: ALERT: Power OFF before changing Firewire or switching HDV/DV" the last two posts are the complete new guide to a DIY preventative fix. It looks complicated but its not really and more importantly it works! The first post on page 9 is a link to some (quickly taken) photographs of this and other well-tried mods. Many of the things I've found useful on my other cameras. The shots are poor, excuse me, I didn't have a decent stills camera or lights to hand.