Hi guys,
After I read this topic a few days ago I thought it would be a good idea to test my K5 (SN: 39944xx, made on 21st of January 2011, replacement for the a first stained body).
And guess what ? It has stains ... Right in the middle, 4 beautiful spots. The body was extensively tested by me in the store when it arrived and it was free of stains (it had just a dust spot). So, it looks like they are developing in time. LV and movie recording weren't used more than a few minutes (for a total of 30 minutes). Shutter count is around 3k.
Two raw files can be found
here (non stained / stained).
I guess I'm a just a very bad luck guy
.