Thanks for the reply. First of all: Sorry, I was looking to the wrong reporting window. After looking at the one you posted as a screenshot, I see nothing now. Thats a bit of a coincidence. As of today a support engenieer had to flush the reporting db, because it corrupted after a upgrade from 7.4x to 7.5x. I will have at look it tomorrow. Do I have to use the proxy to see the URL's? Our web-programmers fear proxies, so that feature is disabled.
Web Security is done with the HTTP proxy, so that report will continue to be blank if you aren't using the proxy. If you wanted to run the proxy in a transparent mode, you could put the IPs of the programmers' computers into the 'Transparent mode skiplist' and continue to allow their web access via packet filter rules. Their access then would not be trackable, but everyone else's would be.