Bugzilla Appliance sends broken links

Our Bugzilla Appliance (just downloaded and installed on ESXi 5) sends broken links:

/show_bug.cgi?id=2

Actually for a user being able to click that link, it must be:

(bugzilla is a CNAME we added to DNS for this machine, as the applicance itself seems to have no name)

How to fix that?

Thanks!

-Markus