Assume that many users access a public folder on a Microsoft Exchange Server 2010 Mailbox server at the same time. In this situation, the Microsoft Exchange Information Store service (Store.exe) may stop responding on the Exchange Server 2010 server. Additionally, if you run Performance Monitor, you notice that the value of the RPC Requests performance counter for the MSExchangeIS object is high and does not decrease.
This issue occurs because of a deadlock in the Exchange Information Store service.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.