I'm not sure how you testing the hardware but there usually is not a lot of Linux support for hardware that is "brand new". there is usually a little development time to get things in line and bug free.
As far as a mobo that works with linux thats a pretty broad question. Most distributions post a hardware compatibility list of some sort. This shows what hardware they support and are working on. I've never had a mobo thats broken a Linux install before so I cannot point you away from any brand.
***I Highly recommend that before you throw that mobo away and move on to another that you try loading knoppix up on it. It's a live CD so there is no install to go through and it's hardware detection and setup is Very good.***
If it works with knoppix you at least know that it is Linux compatible. Get knoppix at http://knopper.net/knoppix-mirrors/index-en.html