USRP2: usrp2_siggen.py problem

Hello,

I have been trying to test the USRP2s by transmitting a CW tone at
2480MHz using usrp2_siggen.py with one USRP2 (with XCVR2450) and
receiving it with the other using usrp2_fft.py. The exact commands that
I issue are:
Receiver: usrp2_fft.py -f 2480M
Transmitter: usrp2-siggen -f 2480M --const

After some time (anywhere from 30sec to a few minutes), the USRP2 that
transmits the signal stops doing so and no longer responds even to
find_usrps.py command. I must physically unplug the power cable from
the USRP2 and plug it back in order for it to work again.

I have tried using different USRP2s as the transmitter, thinking that
this is a hardware problem, but the behavior is similar. The problem
was originally found when using firmware build 11163. After upgrading
the firmware to 11370, the problem persists.

The gnuradio subversion build that I am using is 11619.

Any ideas of how I can debug this? Has anyone else has experienced
similar behavior?

Thanks,
Ilya