If the spider friendly pages fail in threads then they will also fail for the IIP. By default IIP is spider friendly, so you will need to user the non-spider friendly files.
Have a search for spider on these forums, you might pick up one or two tips to get yours working (not sure if you are on on your own server or not). I know that mine initially failed, but I made a change to the server and all was well (that fix is posted somewhere, can't dig it out at the mo)