Beginning on 7/17 time machine quit backing up my virtual machine file. In the past every time I used my virtual machine, time machine would back up the entire machine on the next backup. I'm using parallels 7 desktop for mac with the latest updates from parallels running on OSX Lion (also with the latest updates) Virtual machine setting have not changed and the "Do not backup virtual machine" checkbox is unchecked. Smartguard is disabled. Any idea what may have caused this?