ok... this problem is partially solved...
I found out, that when I set the frontoutput to plughw:0 in xine.conf and choose manually configuration in linuxmcesetup... The sound is available at spdif and analog output...
I didn't manage to get sound via hdmi yet, but that seems to be related to the NVIDIA Chipset (ASUS M3N78-EM)... with actual kernel and alsa configuration the HDMI out appears at aplay -l... but its not possible to hear sound...