Joystick port problem of a Diamond MX300

I just built a new pc for my stepbrother. I am using the ASUS CUSL2-C motherboard w/o onboard sound. My only problem is with the joystick port of the sound card. I used the Diamond MX300. Very good surround sound and now really cheap because it is old. I have this same card in both of my pc's and also in my brothers. The problem is that the joystick port does not show up under sytem devices. It should be auto-detected after loading the sound card drivers but it isn't (it also isn't showing the MPU-401 device listed). I've tried swapping sound cards but no change. The sound card is functioning fine otherwise. Any suggestions?

In various forums I've been to I have seen several posts of people having trouble with the CUSL-2 motherboard. It might be worth checking the Asus site for a BIOS update or patch for your problem.
The only other thing I can think of is a jumper setting, but the MX-300 is too new a card to still have jumpers.
Maybe the old "try a different PCI slot"? <IMG SRC="smilies/rolleyes.gif" border="0">

The MB shipped with the latest bios and I've already tried the different PCI slot. Just hoping someone else has seen or experienced this problem. Thanks for helping.