Consider the following scenario:
You install Microsoft Forefront Threat Management Gateway (TMG) 2010 Service Pack 1 (SP1) and Exchange Edge 2010 on three computers that are running Windows Server 2008 R2. A stand-alone array contains these three computers.
You enable the E-mail Policy feature on the array.
You use this array for email message protection.
You change the Format option to French (France) in the Region and Language settings of Control Panel
You click Copy settings in the Administrative tab of Region and Language settings.
You click to select the Welcome screen and system accounts check box to copy your current language settings to the Welcome screen and system accounts, and then you restart the computer.
You increase the default value (20) of the MaxInboundConnectionPerSource setting in the Exchange Management PowerShell program after you restart the computers.
You run the Process Explorer program to check a short CPU spike on the Managed Control (IsaManagedCtrl) service of Forefront TMG.
In this scenario, the MaxInboundConnectionPerSource setting reverts to the default value.
This issue occurs because the number format is not English. Therefore, a parse operation fails when the IsaManagedCtrl service tries to convert the MaxMessageSize value from a string to an integer.
To resolve this issue, install the software update that is described in the following Microsoft Knowledge Base (KB) article:
2288910 Software Update 1 for Microsoft Forefront Threat Management Gateway (TMG) 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates