I had a similar problem before, and my symptoms were identical. It was on a box that also ran windows, and when windows auto-configured my PnP sound card, it gave it a different value for the IRQ than I was using in Linux. The value I used in Linux was the same as the IRQ for my legacy ethernet card. I changed a jumper on the nic, and viola, it worked. Obviously, your problem is not identical, but I would bet that it is a IRQ or resource problem.