My name is Stefan and I am currently trying, within the scope
of my PhD project, to install a Leica camera to work with a Linux

Has anybody any idea where to search for the problem? I checked that the
camera is in the list at and so is the
firewire controller.

The camera is in the list, but the IIDC column for your camera is empty.  That usually means that the camera does not work with libdc1394.  Leica camera drivers have a TWAIN interface you could use, or you can request a camera SDK from Leica, but both options will only work on Windows.  Micro-Manager ( currently supports Leica cameras through TWAIN and is working on full support through the Leica SDK.