Problem with Bugzillaintegration

Hello,

I have installed Teamcity 6.0.3 and Bugzilla 3.6.3 with rpc enabled.

The Login works, but the connectiontest fails with the following:
Error: Failed to parse server's response: The element type "methodResponse" must be terminated by the matching end-tag "".

What does it mean? What can I do?

Thank you

ph0e