Only posting this here for more 'coverage', and regarding the 'serious grief', this is the short version
The new PS3 3.60 firmware update deleted all my settings for some unknown reason, so it asked for my email address, password etc which were all auto-filled anyway. I inadvertently logged on with my old details because of this auto-filling (I'm still not sure why those details were even there, there's only one user account stored on the system), and this somehow meant that all my save files are now connected to my old PSN ID...
I can copy them back to the newer ID via a triangle button press, but there doesn't seem to be a way of doing it as a batch (unless I use a USB stick?
), and I've no way of knowing if they'll even work properly or if I'm inadvertently corrupting them or whatever the fcuk until I get the time and patience* to test them 
This all seems to be a result of Sony's attempts to introduce cloud storage and keep out the hackers. Anyway, FYI, and I'd appreciate any knowledge you think might help
* I'm not in the mood right now as you can imagine.
