We have just upgraded from 4.0 to 2011 and we are now experiencing random timeouts and loss of the UI. It eventually comes back but it can sometimes be down for 20 minutes or more. During the outage both the SQL server and the Dynamics server are both responsive and do not look to be under heavy load. We have added the OLEDBTimeout and ExtendedTimeout registry keys and set them at 30 seconds. I still see lots of messages about exceeding the 10 second timeout. I have also moved all CRM SQL system jobs from the middle of the day to staggered intervals in the middle of the night. I'm not sure what else to look for.
Thanks,
Glynn