There is a bug in Ubunty Jaunty which cause Trac to have errors.

 Attachments do not work, the admin interface for milestones doesn't work properly - and there may be other issues.

The bug report is at https://bugs.launchpad.net/ubuntu/+source/trac/+bug/369792

And the solution is 

"go to http://packages.ubuntu.com/karmic/trac
and scroll all the way down. There you'll find a download link for the
karmic package which you can download and install via

I just started on a project that was using trac and subversion but they weren't integrated. I love the cross referncing trac provides. It can really help explain changesets and show how an issue was resolved.

The steps to add subversion to trac are