Problem with hostname in URLs

Hi,
I nearly have the same problem as Timothy yesterday.
I currently set up a request tracker 3.6.1 on debian 4.0.
Most of my links on my request tracker are broken.
[Home] --> http:///
[Simple Search] ->> http://search/Simple.html
[Tickets] --> http://search/Build.html
Images can’t be loaded cause of same problem.
Sure I have set the WebBaseURL in RT_SiteConfig.pm - any change
doesn’t affect anything…
Maybe I have just overlooked something during installation?

So this is the message of Timothy yesterday:

#Fixed
#I believe that removing a trailing slash from the DocumentRoot
directive in the VirtualHost definition for RT did the trick. That
trailing shash has been there all along - but I guess after the update
it now #matters.
#---- Original Message -----
#From: “Timothy M. Pearson” <tpearson[at]ois.pittstate.edu>
#To: “rt-users” <rt-users[at]lists.bestpractical.com>
#Sent: Thursday, June 25, 2009 11:05:19 AM GMT -06:00 US/Canada Central
#Subject: [rt-users] Hostname missing in generated URLs after update
(CentOS 5.3)
#Hello,
#On Jun 20, we did a routine update of the CentOS 5.3 box running RT/
RTFM/RTIR (all the latest versions). Right afterward, the host name
disappeared from all the URLs in RT. Users can still log in, but all
#the links on the page have the host name missing.
#A fresh install of the latest RT (with no plugins at all, just bare
bones RT 3.8.4) on a CentOS 5.3 box that was fully patched prior to
beginning the RT installation results in exactly the same behavior.
#Examples:
#[Home] --> http:///
#[Simple Search] ->> http://search/Simple.html
#[Tickets] --> http://search/Build.html
#and so on.

His update in the apache configuration didn’t solve my problem.

Greets, Lars