Okay I'm starting to lose the plot now. We've got an Aruba Controller setup to authenticate via WPA and login to our domain. However when more than a few (three or four) clients try and connect every other client will bring up errors like "Domain is not available" et cetera. However when using the guest SSID which uses internal authentication this doesn't happen and everyone can use it?

Any ideas, I'm using IAS on a windows 2003 server for the authentication have I missed anything?