Morten,
If you had sharper images with the K10D and this lens, then I'd hazard a guess to say that the focus is fractionally off on the K20D with this lens.

Looking at the shot, the cluster of purple flowers just in front of the light house (the ones horizontally centre of the light house, about 2/3rd between the bottom of frame and lighthouse) are sharper than those closer to the lighthouse.

It looks like a small amount of Front Focus.

I'd suggest using a focus chart, a tripod, and using the Custom menu to Adjust AF for the particular lens.

That should sort it out

HTH!
Matt

What I found in my AF540 was the mechanics of the locking pin were a touch suspect, plus a witness mark on the moulding stopped it from moving correctly

I disassembled the locking pin and used the edge of a scalpel to carefully shave off the witness mark on the pin so it doesn't snag.

Never been a problem since

Matt

PS. The 'witness mark' is the evidence of injection moulding. In this case, a fine protruding line. As the injection tool makes more pins the tool wears out slightly and the pin gets slightly larger, and the witness marks more pronounced.

...maybe it stuffs up the SDM motor when over-clocked?
(Or some SDM motors at least)
Perhaps that's why it's been scaled back.
Who knows
Matt

"A" is (manual focus), auto Aperture
"FA" is auto Focus, auto Aperture.

Hope that helps!
Matt

Looks like HDR to me
The "HDR look" you speak of is actually just tone-mapping.... usually over cooked

The billiard room shows the most obvious signs. The RHS of the bookcase should be in shadow (in fact there is an obvious shadow across the floor), but the brightness of the books makes it look unnaturally bright.

You could do it with manual exposure blending in Photoshop, or it could be HDR software (with the controls in the "sensible" region!).

I do remember seeing a very good Photoshop multi-layer room image in one of Katrin Eismann's books. It was detailing handling multiple light sources with different white balances. The photographer had shot RAW, then processed multiple output images for each light source and hand blended.
The result was well worth the effort.

Will see if I can dig up the reference...
EDIT: think it was page 133 of "Photoshop Restoration and Retouching" - alas, not available on Google books

Matt

Yes, there is a definite similarity! I was going to say Canon... but obviously they outsource too!
Matt

It does make you wonder whether the flash manufacturing has been outsourced

Regarding the OP - the AF540 is easier than the AF360. It is possible to remove the hotshoe mount with a small screwdriver (ie a jeweller's screwdriver). The hotshoe mount has a small connector - so you can remove it from the main body.

Matt

You did a good job of cloning.
Personally I'd be inclined to go straight for a background replacement using layer masks in PS Looks like about half hour's work...

Did you want me to have a go on this size image (or email me a full size and I'll do it for you!)
Matt

I've seen on the Internet a Windows application that enables Debug mode for the K10D via the USB connection (without changing the firmware)

Do also check which version of K10D firmware you have too.
Matt

You could try ringing Asahi Photo (assuming you're in the UK). Perhaps the Pentax shoe mount will fit?
http://www.asahiphoto.co.uk/

HTH!
Matt