So close and got panic
EDIT: Never mind the original question, got things running on my Kaiser now.
If anyone cares:
I installed GenY to the device, moved the content of warmdonud to <sdcard>/andboot and renamed default-kaiser.txt to default.txt (deleted the original default.txt), run genY and selected android, pressed the D-Button, ignored the warning as the phone won´t get altered, installed, waited, waited, waited (ignored errors on the screan) - DONE.
So damn easy once U have done it.
In the meantime I realised that I had a hell bunch of trouble 'cos my .NET Framework was installed on storage card and seemingly at some point the system does not have access to the SD. (oh yeah, btw, that´s the solution for those __boot_mainandroid problems! Install .NET on your device.)