wifi asks for username AND password for iPhone

Hi!

So I have moved into a new apartment, and when my iPhone finds the router and tries to log on, it asks for a username AND a password. When I use my Macbook, it just asks for a password, which I enter and get no further problems with.

I have tried entering the router's details manually using the 'Other' feature in the Wifi settings, and still cannot log on (either with WPA or WPA2).

Any idea what's going on here? No one else I know of has this problem!

Thanks!