My GRD20 has developed an identical problem. The first time I noticed it, I removed and replaced the battery, and the fault cleared, but not since the second time. The camera is about 20 months old, and has had very little use, and no rough handling. The first time it happened, the camera was connected to a PC via firewire, but it had operated fine in this manner before, and this time it was out on it's own, so I don't think that is likely to be an issue, but I suggest it in case anyone can correlate my experience with theirs. More relevantly, can anyone tell me what the remedy is?