Consider the following scenario when the Office Communications Server Channel Service service is started on a Microsoft Office Communications Server 2007 R2, Group Chat server:
The time is incorrect on the Office Communications Server 2007 R2, Group Chat server.
The time is correct on the computer that is running the Group Chat database.
Note This causes the time of all received messages to be incorrect in a Group Chat client.
In this scenario, you correct the time on the Group Chat server. However, the time of received messages is still incorrect in a Group Chat client.
This issue occurs because the Channel service caches a time skew value when it starts, and then uses this value during the whole session. This time skew value is added to all the messages that the Group Chat server send to the Group Chat client.
Note The value of the time skew is based on the time difference between the Group Chat server and the Group Chat database.
To resolve this issue, install the following cumulative update:
2491973 Update package for Office Communications Server 2007 R2 Group Chat server: March, 2011
To work around this issue, restart the Channel service after you correct the time on the Group Chat server.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.