I'm fairly new to administrating this network but I recently upgrade our NLB terminal servers and also updated from Outlook 2007 to outlook 2010. Now the users are prompted after clicking on the icon to enter their username and password again before accessing their email.
Here are a few facts I know of.
1. Exchange 2007 in up to date- read online to install the rollups to resolve this issue, it didn't
2. Our TS servers are up to date
3. No authentication issues on TS servers- users able to access files as norm
4. Our TS servers were fresh installs, fresh office 2010 install but they have roaming profiles setup on this network so files are moved around, possible issue with file created in 2007 now opening in 2010?
5. Not a permission issue, happens on my admin account as well