Audio Dropout Problems on D820

Hello,

I have problems with my D820 that I can’t correct no matter what I try.
Audio dropout is the symptom and happens in any application that uses sound: Sonar (recording application), Forte Performer (soft synth hosting application), Windows Media Player, watching movies or videos online, etc.
I’ve tried adjusting latency, experimenting with the buffer, and lately bought a new Hard Drive that will be dedicated to just audio (ie: no internet, no network connection to my Desktop, no superfluous software, etc.
I can’t even get it to work correctly with this new drive which has nothing else on it but the Edirol UA-25EX soundcard! The only thing I can think of is perhaps it’s something to do with IRQ. Is there a way to force the assignment of a lower number?
Whenever I’ve installed the Soundcard, (and from what I read, because of ACPI), it just installs down at the very bottom of the IRQ list. I don’t really understand this stuff, but from what I’ve read (the M-Audio site has an article on IRQ’s), you need an IRQ slot of 15 or lower (physical IRQ’s), and one that isn’t shared.

The IRQ assignment is low (23, which would make it a virtual IRQ, and it’s all the way at the bottom of the list).
I’ve checked per the M-Audio article, and although it’s not shared with anything, the article also mentions that you can’t see if a virtual IRQ is shared. How can you reassign to a lower IRQ if you have no control over the assignment to begin with?
I’m not even sure this is necessarily the answer to my woes, but it’s something I haven’t tried. As you can see below, there should be more than enough processing power to run a few soft synths inside of either Sonar (Home Edition) or through the hosting software Forte Performer.

I’ve been using the USB connection in the back of the computer (which is dedicated to the soundcard only) because a few people online mentioned that the ones in the back are more “directly connected”, whatever that means….

I’m totally frustrated with this….

Please help!

Link to the M-Audio IRQ article:

M-AUDIO - Knowledge Base

My info:

Dell Latitude D820 (Intel Core 2 Duo T7200, 2GHz, 667Mhz 4M L2 Cache,
2GB DDR2-667 SDRAM, Toshiba 7200 RPM SATA Drive.

Thanks!