Hi,
I have currently built osmocombb on Ubuntu. I have checked it with a Linux mint box and my ftdi cable gets unplugged as soon as it gets plugged in.
I did not understand what you mean by the above statement. I am not an advanced linux user.
Before you plug in the cable, run this command in terminal: tail -f /var/log/messages
Now insert the cable to the computer and check what is written in the terminal. This should help you in figuring out what is wrong.