Went to add a user to my buddylist, received the following error:

method:    IMSubscribeRequest
msg:    system failure: java.lang.IllegalArgumentException: Illegal JID: so'connor@saintsmed.org
code:    service.FAILURE
I have a feeling this error has to do with the apostrophe, but since zimbra allows apostrophes and hyphens is the username I can't see why it wouldn't be allowed in the IM as well.