Green dot: dust or faulty CCD?

I've started to notice a green dot (actually more shaped like a +) in my pictures taken with *istDS. It's fairly in the middle of the pictures, and hence quite annoying. Advice from Pentax was simply to send camera back for inspection, and made it sound like dust. However, I thought dust would show up as black, not as bright green?

Here is a sample both at 1:1 and zoomed in:
http://slothy.co.uk/dot.jpg

Looks exactly like those I had on my first *ist D - 33 of them if I remember correctly. I was told it was a fault and the camera was replaced. 30 odd of them was, to quote the dealer, completely unacceptable. One may not be. But a fault nevertheless IMHO.

Thanks for the reply malcolmk. I've never had dust on my *istDS yet (touch wood), but found it hard to believe that this is how dust looks. Found Pentax's reply to follow their cleaning procecure in the manual (blow air onto mirror / CCD) an odd suggestion for fixing this.

Guess the camera has to go back. Pray it is returned before my holiday starts.

I had dust in the works only once; serves me right for swapping a lens on the middle of a field on a windy day. Dust looks just like you would guess, a dirty black mark in the viewfinder or on the photo. Yours is quite different and is absolutely the same as my stuck pixels - though I had red and blue ones too.

Best of luck battling with that one.