|First, disable the onboard audio and use the M-Audio card only.|
If that doesn't solve the DPC problem, download the latest driver from M-Audio. If you're already using the newest driver, try an older one or two. While new drivers often fix known issues, they sometimes introduce new bugs in the process!
If software doesn't whip your card into shape, try running it without any USB devices plugged in.
Nothing? Then move it to another PCI slot. If you have one, test it in a different computer--preferably one with an Intel chipset, as they tend to be the most compatible.
If nothing works, you probably have a bad card. As a last resort you can try to persuade M-Audio to send you updated firmware for your card.
I once had an Auzentech X-Fi Prelude sound card that caused DPCs and hardware interrupts on every motherboard I tested it with, including my i925-based "guinea pig". Turned out to be a bad card, even though it had no problem putting out insanely great sound.
HTPC | Pentium M @ 2.82GHz, 2MB L2) | 4GB | 1.0TB | Radeon HD5750
Blu-Ray | Win 7 Pro | HDMI out to Onkyo TX-SR707 AV receiver