sound problem

[crnholio]

hi list.
i'm having some problem with my Media CMI8738 onboard soundcard: i can only use one output channel, f.e. i've set my xmms up to use /dev/dsp0.3 -> works fine: 

fstat | grep dsp
crnholio xmms         183   14 /           756 crw-rw-rw-  dsp0.3  w

now i start a new xmms session and change the audio device to dsp0.1 -> the first session is still playing sound, but the 2nd doesnt, but fstat shows: 
>fstat | grep dsp
crnholio xmms       86019   11 /           750 crw-rw-rw-  dsp0.1  w
crnholio xmms         183   14 /           756 crw-rw-rw-  dsp0.3  w

i haven't compiled the "options PNPBIOS" into the kernel, but i don't expect that to be the source of my problem, or am I wrong?
i would be very glad if somebody could help me solve this MAJOR problem :).

--
greetings, 
crnholio