High CPU, possibly due to audio driver

I originally posted this in the Drivers forum, but I didn't get a response in over two days. I hope you all don't mind me posting this here.

I have a Macbook running Windows 7 64bit through Boot Camp. Whenever I use audio on my computer, either the built in speakers or headphones, the CPU spikes up. Using Task Manager, I was able to narrow down the problem to the "NT Kernel & System" process. The CPU spikes up about 50% whenever audio is used. If I close all the programs using the audio, the NT Kernel process drops back down to 0% like it should. After some searching online, it seems like this might be a problem with my audio driver. I checked for recent driver updates and then tried to uninstall and reinstall the drivers, without success. My audio driver's name is Cirrus Logic CS4206A (AB84) if that helps, and I have version 6.6001.1.39 installed.

I've dealt with this problem for several months now, so unfortunately I can't trace the issue back to the installation of a specific program. It might even date back to when I installed a new hard drive which I believe was January last year. I tried narrowing down the issue through the use of KrView and xperf, but those programs don't seem compatible on my computer. They load the Command Prompt screen and then close a split second later.

Thanks for the response, Matt.

I'm probably missing something, but I searched the Apple support site, and I didn't find a page that listed the chipset drivers. Would the page be under a different name? Would they be included in the firmware updates, perhaps? I did verify that I have the correct version of Boot Camp installed. I believe I have the 2010 version of the original Macbook line, if that helps. This was the page I was looking at: http://www.apple.com/support/macbook/

I actually tried uninstalling the drivers and having Windows reinstall them before making my first post, but I'll probably try it again. I just forgot to mention it earlier.