We have had multiple issues with upgrading to 2011. The scheduler didn't work, they fixed that, all of act didn't completely load 2011 on my assistants computer got that one fixed.
This one when a new contact created it won't save, the phone number will not format. I would seriously think twice before putting 2011 on if you have a business this has taken too much time. I upgraded because I wanted to merge my database of about 11k to another one that has a few thousand and thought I should use the latest. I think we had 2009