I got my K5 swapped for a new one, at Park Cameras UK. Very good service.
Quote: I'll send my camera in after 11 months, because of resale value
That a good strategy, although you need to check your local laws on that. Here in the UK, after 6 months I think, it is no longer the default legal position that the defect was "inherent" and they are obliged only to
repair the item (so you might be without it for a long time, and you won't get a new one back).
Quote: But i seriously dont see what the problem is with the stain, its invisible in 99.9% of my shots and so very very very easy to edit out of the .1% it does affect.
Probably true for a lot of people. It's visible in about 5% of mine, and then it is very visible. I do F22 shooting in specific situations, a lot.