WATS Server - Transfer stopped/TDM Status errror

WATS Transfer between servers are based on WCF (Windows Communcation Foundation). One key requirement for WCF is that the machines must be synchronized with regards to time. Maximum allowed clock skew is 5 minutes. If the clocks on the involved machines drift more than this, the sending server (local server will report one of the following exceptions:

The security timestamp is invalid because its creation time ({creation date/time}) is in the future. Current time is '{current date/time}' and allowed clock skew is '00:05:00'.
or
An unsecured or incorrectly secured fault was received from the other party. See the inner FaultException for the fault code and detail.

The second message can be caused by several other things, but most often time skew is the reason for this message.

Resolution
Adjust the clock on the machines.
To avoid this in the future - set up automatic time adjustment.
Windows Server: http://support.microsoft.com/kb/816042
Windows XP: http://support.microsoft.com/kb/314054
Windows 7: is automatically set up to use time.windows.com
If the machines are joined to an active directory domain, time sync is set up automatically to use the domain controller(s). The network administrator should make sure the domain controller(s) are synchronized with internet time.