Thanks for the reply, but is it restricting across your whole site during testing (i.e. are the changes always global regardless where you apply them)?
I've just tried again, this time all I did was change the 'Edit Feature Settings' on a virtual application beneath the website root to 'deny' access to unspecified clients, and after an iisreset all my websites came back with 'denied messages'. The 'Edit Feature Settings' on these other webs all show 'allow' access to unspecified clients, so somethings not quite right.
I want every website on my server accessible except the one I'm applying restrictions to. BTW I do this quite successfully on another IIS server without the dynamic IP restrictions (i.e. the original restrictions), so I'm guessing its DynIP not me!!