BurnartOz: PROBLEM SOLVED!
The culprit is Avast antivirus. My desktop computer is only online if I hook it up via USB tethering to my phone which doesn't happen very often but it's still a good idea to keep antivirus and security software on there. I've been using Avast free edition for a number of years and never had any issues previously but the version currently on the computer definitely prevents the pics saving. I tried disabling Avast until next startup and suddenly pics are saving again. Restart Avast and no pics saving. Must have updated Avast around the same time I did the 2.62 NMS update. Not sure if there is a setting somewhere I can adjust to prevent the problem - I've always assumed security software won't interfere with programs legitimately installed on my machine. Like I said, never had an issue like this before.
dashiichi did suggest that when I originally posted - not sure why but I seemed to have neglected or dismissed the idea sorry about that but thanks!
No worries (about that ... about Avast, yes worry ;-)
I can absolutely understand Avast being protective about applications, particularly those with active internet connections, that are writing files to the system. That would be fine
if Avast notified the user or even simply made a log entry in the protection log. But to block the writes and do it silently is A Bad Thing.