server port number greater than 4 digits

when creating an account to my server which has a custom ssh port 39533 i'm not able to save it. it does it on my mac pro and my macbook pro although i only made a screen cast from the mac pro.

here's the screen recording of this behavior. http://bit.ly/AAMlAL

in the video i first create an account and leave the standard port (22) in place. next i create another account with a 5 digit port in which it will not save. i then reduce the port number by one digit then it saves with a 4 digit port number.

any ideas?

thanks!