http://www.jcdeshaies.com/
Hi I see your using Protools, if you are not doing so already download this free app from above link. Protools pref and database helper.
I would first delete all the pref files and then see what happens. If this helps I always delete com.digidesign.protools plist, Digidesign Database folders and Volume folders every day before I start work !!
This would at least eliminate a to a large extent a Protools problem. As Jay said it does sound system specific.