Asus P5B Onboard Soundmax - 5.1 Surround + Headset?

Hi there. I posted this in Asus's forum here but am posting to usenet
as well for greater visibility.
(Asus post at http://vip.asus.com/forum/view.aspx?...luxe%2fWiFi-AP
or http://tinyurl.com/ywllar)

Motherboard: Asus P5B Deluxe WiFi
Onboard sound: Integrated High Definition Audio 7.1 (Analog Devices
Soundmax)
Case: Antec P180
Speakers: Philips MMS460 5.1 surround

Is there any way, using the onboard sound, I can hook up my 5.1
surround sound speaker system *and* a headphone/mic combo headset
simultaneously?

My speaker system is a Philips MMS460, with analog 1/8" jacks for
front L/R (green), rear L/R (black), and center/subwoofer (yellow).

I upgraded the sound drivers to 4580, and am able to hear either,

- Surround Sound by hooking up the speakers appropriately, and
DISABLING AudioESP,
or:
- Headphone/Headset sound by setting the speaker config to 2 speakers
and hooking them up

However, when I have the system set to surround sound, I can't just
use a splitter at the front L/R jack because the sound that's output
there is frequency-filtered (I'm assuming this here based on how it
sounds), and sounds like crap.

Ideally, I'd like to use the front mic/headphones connectors on my
case to hook up my headset. Selecting the option SoundMAX Control
Panel | Preferences | Independent Front Headphones sounds like it
would work, but all this seems to do is mute the output on the front
jacks.

So... Currently I have to swap cables and re-configure the system for
2 speakers vs 5.1 in the control panel each time I want to swap
between speakers and headphones.

I'd prefer to keep w/ using the onboard sound as it works fine for me
and should be able to do what I need, but as a final alternative, are
there any cheap (<USD$50) PCI sound cards that will do what I need?
(Not SB Live, as these have problems w/ sound in World of Warcraft
post patch 2.0)

Any suggestions/help? Thanks in advance. Please post replies to usenet
please; from email is spammed to oblivion.