I just updated to the latest release of both XBMC and MC360. Upgrade was done by renaming the old XBMC directory and uploading fresh new versions of both. I then copied back the XBMC\Userdata directory to preserve settings and database etc.
Almost everything was working fine except I noticed that a password protected (locked) share was accessible without being prompted for the password (not good given what I have available in it!!!). I found that the Master Lock was disabled. It did allow me to go through the motions of enabling it and entering the password twice. But if I then exited from that and went back to my video bookmarks I was still able to get into the protected one without a password. Also pressing the white button on a share did not reveal any of the lock settings. I went back to the Master Lock settings and it was disabled again!
I did all this 3 times to ensure I hadn't made any mistakes but the results were always the same. The setting of the Master Lock just doesn't seem to stick. My final attempt was to switch to PMIII and try using that. It all worked first go. It allowed me to set the Master Lock and then my protected share worked as expected. I changed back to MC360 and everything was still working fine.
So it seems there is a bug in MC360 and its ability to save the Master Lock settings.