Sparfun Wifly shield and FTP Server

In my new Arduino project, I am using the Sparkfun Wifly Shield(Access Point Mode) to use my Arduino Mega like Wireless FTP server. I am using the Wifly GitHub library (https://github.com/sparkfun/WiFly-Shield) and the FTPServer library created by gallegojm (https://github.com/gallegojm/Arduino-Ftp-Server). As a lot of us knows, the FTP protocol use a listen port (21) and a data port (ex:65300) to works.

My problem is that I can’t use 2 simultaneous ports on the Wifly Shield!

Does anyone already got this problem? Does anyone have a solution?

For information, my futur project will be embedding on a vehicule.

Thank’s to who will take my problem in account.

Emeric