Since both are folders and changes to one appear in the other then it
does appear as if there's some cross-linking going on here. Don't
expect it to be a 64bit vs 32bit issue, more file corruption and as
long as that's all that's happened then just a curiosity. I'd be more
fastidious with the backing up though just in case it's a sign of
other things about to go wrong. It's not a good sign to have folders
that do this !