Windows 7: No permission to modify files bug/weirdness

I have a problem with my 7. Sometimes - ONLY sometimes (!) when I try to save a file onto my PC, regardless if it's on the desktop, documents folder or on a network share, I'm presented with the error "You don't have permission to modify files in this network location". The file is created but is empty. When I try a second time it always works.

I'm puzzled that it mentions "network location" even on my desktop!



This error is displayed regardless of the application used to save the file.

I think perhaps it could be a bug related to offline folders, as I enabled offline sync with my documents folder on a network share recently. While a network glitch seems logical for such error it doesn't make sense when I save files on my desktop.