I've done some further research. and this is not an actual problem with adium. I also tried to add the name from iChat and it says the name is invalid. plus, i can still add other names, just not this one. so it's either the server or a bum name.
Yeah, this happens to me as well, and I only have 36 contacts. I've been trying for the past day or so to add a contact, and I get the same error every time. What other info do you need from me to solve this bug?