Sorry

I had to manually edit the file /etc/modules and the midi support on pc with maestro3 cards works:

uncomment 'maestro3'
add 'snd-maestro3' and 'snd-pcm-oss'
like in the old /etc/modules file.

I could not understand, why the old /etc/init.d/alsa-autoconfig
or the automatic hardware detection works, the new not.