We have come across a problem with the new Service Pack 1 for Office and the CRM 2011 client for Outlook.
The symptoms are that calendar reminders do not pop up in Outlook which can cause some major problems for the end users.
We found that in our environment, if we removed the CRM 2011 client for Outlook the reminders would start working again. We then reinstalled the CRM client and found that the issue came back. Disabling the CRM add-ins in Outlook had no effect.
This issue is currently being investigated by Microsoft Product Support. I will keep you posted of any fixes that are announced.