You might check with your ISP. I just had a client with a similar issue. It turned out the ISP was blocking port 80. So no matter what we did, we couldn't access the server from a web viewer.
Thanks for your reply. I'll check with them on that. Would changing the port to 591 get around that problem though?
Make sure that the permission groups which will access it by IWP have the Extended Privilege "fmiwp" turned on for them.
File menu > Manage > Security... > Extended Privileges (tab): then select "fmiwp" and chose the EDIT option to assign it to the appropriate permission groups.
You may want to try entering the url as such:
That is how we access it on our server... FWIW.