To all equipment freaks, the most valuable component is the eye behind the viewfinder and the brain its attached to.
For pity's sake how many pixels do you need? I get wonderful A2 prints from my K10d. And given that most folk only ever look at their images on a computer screen of typically about 2 Mpx - all that extra resolution is wasted on them.
I would possibly pay for better noise performance and wider dynamic range, but I certainly wouldn't want anything larger or heavier or more complex than the K10d

Well spotted, of course it doesn't.

On the other points, yes the battery is charged, yes the firmware has been updated and yes the lens was bought in UK so I'll see if the shop can help.

I can reassure Oggy that otherwise my 50-135 is a very fine lens.

Interestingly, I also thought the da*16-50 (which I tried but didn't buy) was rather sluggish focusing.

Hi Petercf - yes a Sigma 10-20 which is fine. To answer your implied question I do think its a lens fault and not a camera fault. The problem is quite variable and mechanical rather than electronic in nature.

There's no accounting for morons. In truth Pentax have too small a market share for Jessops to bother with, but hey, Jessops won't survive 2009.

My da* 50-135 suffers sluggish focusing especially in cold weather. It is generally slower than my old screw drive lenses and sometimes refuses to focus at all. Unfortunately its now out of guarantee. Can anyone recommend a good repairer? Incidentally, this is the best of my Pentax lens collection and is pixel-sharp corner to corner from f5.6

Can't agree with the enthusiasts - I tried one out against my existing 16-45 and it was significantly less sharp at f4 at edges, with some dreadful chromatic aberration wide open. This may have been a bad sample but for a flagship lens there should be no bad samples.