Those that can not get a connection to their FTP server..
What FTP server are you trying to connect to??
IF it's webspace provided by your ISP then you'll find most of them IP restrict the server, thats why it works from your PC (when connected to your ISP) and not from your phone (when your connected via GPRS to your network operator)
Not much you can do apart from using dialup from your phone into your ISP - but at 9600 is way to slow to be usefull.
You need a non isp supplied FTP/Server account which is not IP restricted..