Check your Windows Firewall and make sure that MSDTC.ext is allowed
If that doesn't work, you may also have to add a couple registry
\RestrictRemoteClients : 0
\EnableAuthEpResolution : 0
I just had this problem and called into MS Support. I added the RPC
folder, then added the 2 DWORDs. (If you add them as String values, it
really messes things up and you'll have to use the Repair console to
fix your registry)
There is also a DTCPing program that you can run to make sure DTC is
communicating between machines.
Hope that helps!