Sorry, my German is rusty,English will be better !!!!
The file acpi-support-base is available from Debian repositories.
However this link to Debian repositories is not included in Synaptic BT4.
Either you add the link to Synaptic :
links should be available from Debian website
Search acpi-support-base in google, download the .deb file, install it and install from Synaptics eeepc-acpi-scripts.
It's done, hotkeys works (not all of them...)