I'm running OTRS using the default windows installation, except I've configured Apache to use port 81 to avoid a conflict with IIS running on the same server.  Everything seems to be working ok, but for one issue: the notification emails that include a link to the ticket have links that look like http://myserver.mycompany.com/otrs/index.pl?Action=AgentZoom&TicketID=2 instead ofhttp://myserver.mycompany.com:81/otrs/index.pl?Action=AgentZoom&TicketID=2.  The link fails because the port number 81 isn't included. 
I've tried changing the Core:FQDN setting to add the :81, but OTRS refuses to accept it, at least through the SysConfig web interface.  Is there something else I can do to fix this?