Thanks all. Yes, it must be a setting, I'm sure you're all right. I've factory reset, as per Ken's suggestion (well, it was the easiest and probably a good idea after four years!) and thanks also John and Pentaxophile for your more specific observations which I will check later. So far, no problem, but I'll let you know if otherwise.

Very many thanks, again,

Wolfie.
PS: What a great site!

Hi All,

I've owned a K-7 for three or four years and, with its great Sigma lenses, it does everything I need it to. However (you knew there was a "however", didn't you?) occasionally, usually when I'm trying to snatch a candid or quick wildlife shot, the camera just seems to lock up. Although I've blamed this on the shutter in the topic title, I have no reason to do so, it's more as if some setting is preventing the firing, but I've no idea what this could be. It seems to happen on any setting (I'm usually set to USER, but it can be in anything, P, Av, Tv, etc). It's maybe once every 10 or 20 shots. I really can't remember how long this has been happening; some time. When it happens I usually press the shutter-release button with increasing panic, maybe adjust the aperture or shutter speed, press the AF button, anything, and eventually it works, by which time (we're only talking seconds) the scene has changed and/or my panic has messed up the framing of the picture. Before I take the camera to my repair guy (always difficult to explain a sporadic problem), can anyone thing of a setting or something else that I may be doing to cause this?

Very many thanks, in advance, for any replies.

Wolfie.