Since mint 1.16 (or maybe even before), the kernel has serial port
drivers equivalent to hsmodem. So no need to run hsmodem when you use
mint.
I know it but for me is really strange how for example author of FTP Server for Sting (you know, that greek guy ;-) achieved 115200 Bd, i.e. 10 KB/s when I'm unable to set more than 38400 (and in this case it's also buggy sometimes). What speed do you use and on what hardware?