Bug report source: http://forums.dpreview.com/forums/read.asp?forum=1036&message=33911846
Or, the K-7 is being afraid of working under cold temperature, just like what some K20D units did as reported - sensor artifacts and noise patterns would appear when they were used under just lower temperature?
Update (12-11): According to the discussions here and at the original DPR thread, I have re-visited some of my snow photos and I think that it is not a bug but just the reflection of some snow crystals that could exist at the snow scenes and environment.
Well, I normally could not see snow as there is no snow in Winter at Hong Kong. But still, I took some snow photos before elsewhere in Winter and would like to share two of these here, as below:-
(Taken with a FA 24-90 on a MZ-30; Scanned with a Minolta Dual Scan II - Well, with careful inspection I can also see "White Sesame" in my *film* photo! :-o)
(Taken with a weather-sealed Olympus u-Zoom Compact P&S (at that time it was snowing); Scanned with a Minolta Dual Scan II.)