Sony DSCP10 + MPK-PHA + VF-MP5K - Red Speckle

I've been using the subject combo for a few months now. Pics were fine to start with but, just recently, most pics (both medium and long distance) have collected a red speckle in the right half nearest the flash/diffuser. Macro is still OK. The detritus level in the water is the same or better (UAE/Oman versus The Maldives for example) yet this speckling still persists. I give both housing and filter a good clean externally after every dive although the filter has picked up a superficial scratch which does not coincide with the speckled area. Any thoughts, experiences, solutions gratefully received. Thanks in advance.

Steve

Dubai