Since version 4.0.0 is the TFS plugin not supporting TFS Server 2005 (and probably TFS Server 2008) anymore. It would be nice to say the drop of support in changelog on website
https://wiki.jenkins-ci.org/display/JENKINS/Team+Foundation+Server+Plugin

Also would it be good, to have support for it in the current plugin, to get improvments.
This could be done by separate the logics into new and old TFS implementation.