Problems with xmodem

Hello,

Iam facing a problem, i hope that some can give me a hand in that.
I was able to install Qnx6 on my IPAQ 3870. I was doing file transfer using xmodem via serial port and suddenly it crashed and i was not able to do any transfer anymore (The message I got is “No response from remote system”). I tried another protocols and even i changed the PC that connects to the IPAQ , nevertheless i was not lucky.

Anyhint Please ???

Thanks in advance

Bassel