Another update to my situation:
I have done (another) full install of LM14 Cinnamon on a usb flashdrive (the original, problematic full install is on a flashdrive as well).
I have kept the new install pretty much default - themes, icons etc.
It is fully updated.
There has been no problem at all so far with the desktop icons - they have shown up every boot
I didn't change any of the settings/files as I did in the post above - it just works as it should in this new install.
The original install was the RC
of LM14 Cinnamon, which was just updated -
I wonder if that might have been the problem or contributed to it?
Or if messing around with themes or icons has been the problem.
BTW - the original install on flashdrive is still having problems - sometimes it boots up properly.
Sometimes, it doesn't even get to the desktop after logging in - black screen or just the wallpaper with no icons or panel!!!!
if I Ctrl+Alt+Backspace and log in again, the icons will then appear more often than not.