Sorry for the lack of info. I just saw a problem that I have too and thought to let you know.
This isn't a big problem for me because I use esound for mixing and keep vmix disabled.
When I output to vmix-channel it seems to work but after a while my system freezes and reboots.
It seems to happen with all programs that play sound continuously (players like xmms,audacious, mplayer, ..)
Here is ossinfo output:
%ossinfo -v
Version info: OSS 4.0 (build 1002/200704040156) (0x00040002)
Platform: FreeBSD/i386 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Wed Apr 25 02:14:37 EEST 2007
teemu@veneficus.koti.lan:/usr/obj/usr/src/sys/VENEFICUS
Number of audio devices: 7
Number of audio engines: 7
Number of MIDI devices: 0
Number of mixer devices: 1
Device objects
0: ich0 Nvidia CK8S
1: vmix0 OSS transparent virtual support
MIDI devices (/dev/midi*)
Mixer devices (/dev/mixer*)
0: ICH AC97 Mixer (ALC850) (Mixer 0 of device object 0)
Device file /dev/oss/ich0/mix0, Legacy device /dev/mixer0
Priority: 10
Caps:
Audio devices
/dev/oss/ich0/pcm0 Nvidia CK8S (device index 0)
Legacy device /dev/dsp0
Caps: DUPLEX TRIGGER MMAP
Modes: IN/OUT
Engine 1: Available for use
Engine 2: Available for use
Engine 3: Available for use
Engine 4: Available for use
Engine 5: Available for use
Engine 6: Available for use
/dev/oss/ich0/pcm1 Nvidia CK8S (device index 1)
Legacy device /dev/dsp1
Caps: DUPLEX TRIGGER MMAP SHADOW HIDDEN
Modes: IN/OUT
Engine 1: Available for use
/dev/oss/ich0/spdout Nvidia CK8S S/PDIF out (device index 2)
Legacy device /dev/dsp2
Caps: TRIGGER MMAP
Modes: OUTPUT
Out engine 1: Available for use
/dev/oss/vmix0/pcm0 Nvidia CK8S (VMIX0) (device index 3)
Legacy device /dev/dsp3
Caps: DUPLEX TRIGGER MMAP VIRTUAL
Modes: IN/OUT
Engine 1: Available for use
Engine 2: Available for use
Engine 3: Available for use
Engine 4: Available for use
Engine 5: Available for use
/dev/oss/vmix0/pcm1 Nvidia CK8S (VMIX0) (device index 4)
Legacy device /dev/dsp4
Caps: DUPLEX TRIGGER MMAP VIRTUAL SHADOW HIDDEN
Modes: IN/OUT
Engine 1: Available for use
Engine 2: Available for use
Engine 3: Available for use
Engine 4: Available for use
/dev/oss/vmix0/pcm2 Nvidia CK8S (VMIX0) (device index 5)
Legacy device /dev/dsp5
Caps: DUPLEX TRIGGER MMAP VIRTUAL SHADOW HIDDEN
Modes: IN/OUT
Engine 1: Available for use
Engine 2: Available for use
Engine 3: Available for use
/dev/oss/vmix0/pcm3 Nvidia CK8S (VMIX0) (device index 6)
Legacy device /dev/dsp6
Caps: DUPLEX TRIGGER MMAP VIRTUAL SHADOW HIDDEN
Modes: IN/OUT
Engine 1: Available for use
Engine 2: Available for use