Yes i'm having this issue to.
Becomes worse after display many documents in pane, worst even if scanned images are in.
After killing the process, sometimes it generate even more process.
After Killing all the process, sometimes need to deactivate the pane view and activate
again to restore normal preview.
Sometimes it takes a lot of time to progress to file below, if i wait, going to files above, it pass
the file that shows delay, without any problem.
I add received from Microsoft, in answer to the same issue to uninstall adobe reader and install
latest version. It become a bit more stable, but problem still shows.
Abobe reader: 10.1.0, ATI latest drivers 11-07