FYI, duplicate post (sorry) from my topic--
Reply back from the engineers, via support advisor
"I received an update from our Engineering Team. They advised me that this is a reoccurring known issue with the version of Adobe Reader installed on your device. There are troubleshooting steps they are suggesting we take."
and a little later
"Apple Engineering has informed me that they have received reports of this symptom and are investigating. Further updates, if any, may come by way of a software update, knowledge base article or software release. They also informed me that further troubleshooting would not be necessary."
So they blame Reader. I have deleted reader, verified trash emptied, nothing by that name left on the machine per search in finder, and after reboot, no difference in symptoms. I don't think it's reader. I think it's 10.8.4.