I solved the problem with
different output to the front panel
on my ASUS P5P43TD.
All you need to do is to go to
Onboard Devices Configuration in BIOS
settings and change
Front Panel Type from
HD Audio to
AC97
After restarting you have now Tab called
HD Audio 2nd output
in
Realtek Audio Manager (but keep Speakers tab as default output).
If you can't see that Tab, go to
Device Advanced Settings and change it to
Make Front and Rear output devices playback two different
audio streams simultaneously.
If you choose the other option in
Advanced, you will have only
one stream but from both outputs - front and rear (Yes! It's possible!)
And now you have multiple choice for output in popular applications
such as audio- and video-players, where you can change output to
Speakers or to
HD Audio 2nd output.
As a result my Foobar2000 (audio) and MPC (video) are playing
onto different outputs as I'm typing this post.
For some games you can choose the output too (Black Ops) in game
Sound options but in some of them you cannot (MW II)
BTW if you don't set anything as Default in
Realtek Audio Manager
you won't have any sound in MW II and some other games.