Server virtualization technology has been adopted by more and more companies and some network engineers do not follow Microsoft guideline/best practices to create virtual machine hard disks by simply copy the virtual hard disks and then rename the machine name. This is not supported way of duplicating virtual machine.
I spent fair amount of hours to identify one of the MSDTC issue for my client on one of their virtual machines. I spot the issue until I used the DTCPing tool and the ping is successful but when you look at the log file, it contains some information like following:
WARNING:the CID values for both test machines are the same while this problem won't stop DTCping test, MSDTC will fail for this
After I fixed the duplicate CID issue followed the instructions number 11 in http://support.microsoft.com/kb/306843 MSDTC worked correctly.