>I saw that Rick had also suggested your own HTTPHandler and I'm sure a handler factory is the ideal way to go - but you could just check the handler type and only pass the request to your framework if it's an ASPX page (or other type of interest).

Yes, I would prefer that. But, even if I could find a way to have this GetType() working in VB.NET, by only passing an aspx page to the framework, I would still have the problem of the Redirect not being applicable to the PreRequestHandlerExecute() event.