Track get's out of sync

I have a track with in the project that seems to go out of sync, the track dose have an effect which seems to be making the track out of sync. After some investigation , I learned if I have the media browser open thats the only time this track goes out of sync, Im sure its not the plugin just caus I have multiple instances within the track.. Pretty weird I dont see this happing on all tracks that have that plugin inserted , Perhaps it the effect used and it parameters that loses sync , but most definitley it has something to do with the media browser open... 
  This track has something like a 40 track count and bunch of plugins ect.. Im running W7 64 bit with a roland quad capture . Has anyone else seen this happen ? if You have, see if you have the media browser open.

On X1c, I recorded one guitar track and then a vocal track.  Upon playback, the vocal track was entirely out of sync with the guitar.  Never had this happen before.  I had to delete the track and relaunch X1 and start again.  I was saving my song as a new file before this happened so I assume there was some memory issue.  Never "heard" of this problem before.