When Microsoft Exchange Server 2010 users try to access a public folder, they may experience one or more of the following symptoms:
The users cannot access the public folder. Additionally, these users receive an error message in their Microsoft Office Outlook clients. The error message indicates that the public folder is not available.
The Outlook clients do not respond.
This problem occurs because a deadlock in the Store.exe process occurs when there are two or more users who are trying to access the same public folder.
To resolve this issue, install the following update rollup:
2425179 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.