I had a couple of folks reach out to me in regards to my last post. Apparently they were having problems removing the Guidance Automation Toolkit and/or the Guidance Automation Extensions. If you look at the installation instructions very carefully, there is a link to Tom Hollander's message board post that tells you how to manually remove GAT/GAX. If you have any further problems feel free to post it in the comments here and I will see what I can do to help.
EDIT: Someone who read this post found a few things helpful, but ulitmately even these instructions did not help. The fix was to run the original install as an "admin" and repair the installation. Once that was done, the uninstall worked perfectly. He detailed out his experiences here: http://coolthingoftheday.blogspot.com/2007/05/uninstalling-guidance-automation.html
I tried almost everything Tom mentioned (everything except for the Reg hacking) and was still having uninstall problems (I was getting a 2769 error when uninstalling GAX)...
What did end up working for me was to do an "Admin elevated" command line Repair with the source/original MSI. THEN I was able to successfully uninstall GAX.
In case it might help I also documented my experience here, http://coolthingoftheday.blogspot.com/2007/05/uninstalling-guidance-automation.html