[Xastir] AX.25 problem on Linux

[Rmead at justconnected.net]

Hey all -

I've got a very strange problem with my ax25 setup on Ubuntu. Google 
searches have proved fruitless, so I'm hoping someone here has some 
tips.

I had a working setup and was running xastir over the ax25 port just 
fine. I'm using a tnc-x through a USB to serial dongle. But now, the 
port goes down after just a few minutes of being up. I get the "port 
'radio' not configured" message in any ax25 software, the interface is 
no longer up in ifconfig, and so on. When it's up, it works fine with no 
problems for transmit and receive, in both xastir and digi_NED. I can 
bring the interface up by 'killall kissattach' and re-doing it... but 
this is clearly suboptimal.

To emphasize, this was working perfectly yesterday. The only thing 
that's changed, except for restarting, is that I'm not connected to a 
network (out on vacation in Maine).

I should also note that I'm able to run xastir just fine if I set it up 
as a regular serial KISS TNC, but then of course I can't share the port.

Any guesses?

Thanks,
Robert KC2YWE