I've ran across this problem before too and what I did was run the
proxycfg and rebooted the server. Worked fine after that.

Have you tried stopping and restarting the IISAdmin service and all of its
dependencies? Also you can try flushing the application cache, but I does
not always work for me.

Yip I've tried restarting IIS through the mmc  console as when I try and
restart through the services inetinfo usually hangs! I can't really reboot
the server it's live and the users are already short on patience with it..

Ok, I understand. This is how I solved the not able to reboot during the
day problem. I wrote a batch file that restart the IIS service every
morning at 4 a.m. Since I am doing this every day the system does not hang.
Of course, you will have to reboot the system at least once before trying
this method.

Let me know if you would like the code for the batch file.

At the moment I'll try anything ! The code for the batch file would be
great...