Hi,
I having the same problem with my Canon i630. Bought 2 yrs ago.
I have nearly 40 tapes recorded via the above, all worked fine and were stored correctly. Recently the majority of my tapes started to get dirty- mosiac like pictures/ greyouted.
The camcorder has been professionally cleaned (twice) and by me using the recommended head cleaner. The head drum assembly has also been replaced.
Justt got the camcorder back form repair - recorded new tape (virgin tape) played ok. 24 hours later I played the tape back - dirty again!!! unkn

own!! (as I have not played any of the former infected tapes in my collection).
Not sure why this is happening - the camcorder is going back yet again.
I hope someone can shed some light on our problems!.