I use the latest version of adium (v0.76), i made an upgrade from an older version (dunno the number, but i already had the problem)
I can't add a new jabber accout because its not allowed to type a "|" pipe character on the User Name field.
However I don't have this problem with another client : gaim on my linux box
The error Message is :
"Invalid Input"
The characters you're entering are not valid for an account name on this service
I guess it's a bug as those characters are allowed by jabber