To put all the steps in one place here’s the three recommended:
1. uncheck the drivers in WSUS — http://msmvps.com/blogs/bradley/archive/2008/08/22/time-to-uncheck-the-driver-category-on-wsus.aspx
2. Run the driver clean up tool http://blogs.technet.com/sus/archive/2008/08/20/a-large-number-of-driver-updates-showing-up-in-wsus.aspx specifically — http://www.codeplex.com/WSUS/Release/ProjectReleases.aspx?ReleaseId=16459
3. Run the clean wizard — http://msmvps.com/blogs/bradley/archive/2008/08/05/cleaning-up-wsus.aspx
If after those three steps, unchecking the driver category, running the driver clean up tool and then the clean up wizard in WSUS and you STILL don’t have the monitoring reports working, can you ping me via the contact box on the blog?