It says it supports 2003, but when I run it in Analyze mode it doesn't even report that there are hotfix uninstallers to uninstall. I have hotfix uninstallers in C:\Windows all the way back to 2004. I just redownloaded and unzipped the latest version of the portable version to make sure it wasn't a bad or old copy.
and Yes, I have the option for hotfix uninstallers checked :-)