The following exception is thrown when the plugin is used in HUDSON (not sure about Jenkins...yet)

An error occurred: com.microsoft.tfs.core.exceptions.TFSUnauthorizedException: Access denied connecting to TFS server http://company_build_server.com:8080/ (authenticating as company_domain\company_userId)
FATAL: Executable returned an unexpected result code [100]
ERROR: null

...where the company_domain\company_userId is something like "abc\xyz". The other commands used earlier in the build process ("tf workspace", "tf get", etc) work fine using the "company_domain\company_userId" format.

I think an extra slash "\" is not being inserted. In other words the slashed is not being escaped.

For giggles I tried switching the format of the userId to "company_user@company_domain" the "tf workspace" command (at the beginning of the build) fails. I get an authentication failure.