Anyone else have this particular problem?

I've never been anything but happy with my 717 but I 've noticed this in the last week or so: If I turn the camera on, or switch from playback to camera mode, in bright light with the cap off, things get very overexposed. I mean, shadows go very gray and highlights and midtones are all white. However, if I switch the camera on, or switch from playback to camera with the lens covered (the cap, my hand, doesn't seem to make a difference), things are fine. OK, so the obvious solution is, keep the lens covered until after the camera's on, but can anyone else's experience with the 717 or similar cameras tell me whether there will be other problems down the road, and are they fix-able? Thanks. Would really like to keep this camera as it's been a stellar performer except for this.