After installing an unsigned kernel driver, I noticed that I got an error with playing DRM content on my Zune.  After some digging, I found:

http://blogs.technet.com/askperf/archive/2009/02/24/windows-7-zune-and-the-case-of-the-mysterious-debugger.aspx

It took awhile as when I was searching for Zune C00d2767, nothing came up, but hopefully somebody somewhere will find this useful.