I recently had a real problem getting an iPad to connect to a wireless router on a ETC network.
After much hair-pulling we found a solution on the Allen & Heath website. Basically iOS6 assumes that any wireless connection is also going to connect to the Internet- so it opens a Safari login page. Depending on your situation , it may be a blank page, so you can't get the initial connection made.
The following article from A&H explains how to get around it.
Craig Blackley
Jack A. Frost Ltd.