I think this will happen in IIS 6.0 if it's in IIS 5.0 Compatibility Mode. Right-click Web Sites, select Properties, and go to the Service tab. Ensure 'Run WWW service in IIS 5.0 isolation mode' is unchecked. If it is checked, you should check with anyone else running applications on this server to find out why.
DoEvents: Generating unexpected recursion since 1991