Hi Karn
I found some strange pixels on some of the jpegs taken with "2 sec delay" mode on a tripod......not in the same spot, they move around quite alot.
They're probably sub-atomic particles, with nothing better to do of an evening......LOL ! Very weird and not something I've ever noticed before, as I generally don't do many night shots. If I were you, I'd send an example of this phenomenon in to Pentax HQ and see what their technical bods have to say about it ?
Best regards
Richard