I have recently come up against a problem with using the 'new' wireless network at work. We are using Cisco kit and TACACS+ to interface onto Microsoft's AD in the back end. Technically, usernames should be able to be up to 31 bytes long (not a problem there) and the password up to 254 bytes. However, the web portal implementation that we are running has a problem with my password. It would appear that passwords of up to 16 characters are fine, but passwords in excess of 16 characters don't work.
We are currently investigating this, as it seems like a real problem, especially as we are recommending that people switch to using longer pass phrases, in excess of 16 characters. Hopefully vendors will catch up with this soon, as many still have problems with so-called 'special characters' such as punctuation and other common symbols.