Finally I managed to do a test with our old Amanda v2.5.2 installation. It really worked fine with this version (using passwordlesss SSH) although it really took a lot of time, but that's fine. Therefore I will have to check what's been changed, that will take some time.
>>>>> "Michael" == Michael Schmitz <michael.schm...@meelogic.com> writes: Michael> Ok, I can of course do what you suggested to do a Michael> complete restore. That's fine for now, but will there be Michael> a real fix for this problem? Michael> Our old backup server is still somewhere waiting for a Michael> new "job", and I will re-check whether the problem is Michael> really "new".