i shot some footage earlier today, when played bck, nothing on tape. i tried watching another old tape with footage i know is on it.... but still no picture. there is timecode but no picture. when fast forward(search) the image can be seen but with several bars accross the screen....... any ideas. could the heads be dirty or is it more serious?

Sure sounds like dirty heads to me. Try running a head cleaning cassette for a few seconds. If you've had your XL1 for more than a year without sending it in to Canon Service for a checkup and thorough cleaning, then now is certainly the time to do so. See the "XL1 Skinny" page on the Watchdog.

Sounds silly, but sometimes the plug of the viewfinder has come loose a bit: pls. check.

I've been having the same problem as well! I know it's dirt on the heads because as soon as I use the head cleaner it corrects the problem. Unfortunately I've been really bad and haven't sent my camera in for service in 2 years!! I've been so busy with it that I couldn't part with it. I don't have a DV deck so my camera has to be my record/playback deck as well. I had my head-drum replaced already but it was under warranty then. I would suggest to anyone to buy a DV deck for editing as it will wear the heads out quickly using the camera for editing (as I'm finding out)!
Also press the 'search' quick review button once in a while to make sure your recording! If it's 'blue' with a time code still going, you've probably got dirt!

2 more weddings to edit and then I promise I will send it in to Canon!