Port Redirection (AIM to Jabber)

I had a remote user that could not connect to our chat server using Adium. They were perpetually stuck at “Initializing stream 25%”. After troubleshooting several different things, I came to the conclusion that there location must be blocking port 5222. Part of my reasoning was due to the fact that they were able to connect to AIM without issue.

Soooo…I had this idea. What if I just redirect all connection attempts to my chat server via AIM’s default port (5190) to Jabber’s default port (5222). And it worked! I realize I could have changed the port within Openfire, but then I have to change everyone else’s connection settings. And I also could have requested that the remote user request their location update their firewall to allow port 5222, but there’s no guarantee that they would agree

Having done all this I am wondering, are there any security issues or usability issues this could cause?