500 Internal Server Error on detail view

In the Main View of Hobbit I click on "ssh" of host "blackadder".
I get a page with a "History" button, the lastest message and a graphic.
I click the "History" button.
I get a page with several "text mode" charts and a list of the "Last  50 log entries" below.
The red and green icons in the column "Status" can be clicked.
The linked URLs look like this:

http://XXX.XXX.de/hobbit/cgi/bb-histlog.sh? HOST=blackadder&SERVICE=ssh&TIMEBUF=Thu_Mar_15_10:09:43_2007

But most of these links result in a "500 Internal Server Error" when  clicked.
I guess the green ones with a short duration (only a few minutes) fail.
The red ones always fail.

This also happens with other server side services like "http" and  "conn".
I do not have this problem with any client side service.


Is this normal? Do others have this problem too? What is wrong with  my configuration?

Thanks for your help

Matthias