The TechniSat CableStar HD is supported by Linux since Kernel Version 2.6.33, however without the attached CI module.
05:01.0 Multimedia controller: Twinhan Technology Co. Ltd Mantis DTV PCI Bridge Controller [Ver 1.0] (rev 01) Subsystem: Device 1ae4:0002
The necessary firmware can be found in the package firmware-nonfree since Ubuntu 11.04. This package can be installed with the program “Additional Hardware”. Afterwards, the card is detected automatically and initialized:
DVB: registering new adapter (Mantis DVB adapter) DVB: registering adapter 0 frontend 0 (Philips TDA10023 DVB-C)... DVB: registering new adapter (Mantis DVB adapter) DVB: registering adapter 1 frontend 0 (Philips TDA10023 DVB-C)..
If the modules are not provided by the distribution they can be compiled and installed by hand. A detailed tutorial is available at http://www.linuxtv.org/wiki/index.php/Technisat_CableStar_HD2.