Thanks for the education Kim, but I think I like Clarky's version more.

There are other camera forums?

No need to post in code, if you want people to understand it that is. What on earth is [WTB] supposed to mean to the rest of us on this planet?

The manual stopped-down metering issues are well documented elsewhere here. Some have found a 'cure' by replacing the focussing screen.

If you use any K or M lens wide open, you'll have no problems. It's only when you stop down that you'll see any exposure issues.

Use a light meter and you'll have no problems at all.

More info about the various 400mm's is available here.

My biggest issue would be the minimum focussing distance of the K version, at 8 metres compared to 5 for the M and 2.8 for the A.

That is an original Pentax 'K' series lens, ie not Pentax-M or Pentax-A. It'll have metering issues on a K10D. A superb lens nevertheless. I've no idea what would be a sensible price for it, except to say, not cheap.

As far as I know, all Pentax lenses from the F series onwards (FA is newer) are auto-focus lenses.

You could raise a bit more. You have 2 x 50mm 1:2 and 2 x 28-70's. Sell one of each (keep the A 50mm and the Sigma EX 28-70). They may not make very much but you'll get something for them and you'll have saved some space in your bag to make way for some 'new season' glass.

Did you use fresh/freshly charged batteries?
Was the flash fitted to the camera properly?
Have you had good shots previously?
Have you tried the flash on another body?
Have you tried the flash in wireless mode?

The flash could be faulty, but it's not likely.

I don't think you've really had time to get to know your camera. Maybe a modern DSLR is not for you.

Why are you selling after only two weeks?

You're welcome.

Enough said, I think.