Tuesday Quickie - Transaction Manager Errors are not always what they seem

This one bit me today for the second time, so I thought I'd blog about the problem - more than as a reminder to myself than for any other reason.

On one of our environments, database changes weren't being saved with the following cryptic error message:

Communication with the underlying transaction manager has failed.-- COMException - The MSDTC transaction manager was unable to pull the transaction from the source transaction manager due to communication problems. Possible causes are: a firewall is present and it doesn't have an exception for the MSDTC process, the two machines cannot find each         other by their NetBIOS names, or the support for network transactions is not enabled for one of the two transaction managers.

The actual cause?

A single rogue space in the connection string.

Go figure!