Gain on AEX2400 occasionally goes out of wack

Every once in a while the RX gain gets set too high by the automatic tuning. In my last session with support (great experience by the way), it seems that the issue centered on the hardware echo cancellation module. Went through, reloading the AEX2400 driver with vpmsupport=0 and that seemed to fix it. Re-enabled the module and went my merry way till a few days ago the same problem popped up with the saturated line that could not recognize DTMF and locked in a continuous loop off the hook.

As a stop gap I have set vpmsupport back to 0 in the modprobe.conf. I would like to re-enable the echo cancellation but cannot allow it to randomly lock up like that again. What to do?

Asterisk 1.4.18.1
Zaptel 1.4.10.1
Wildcat AEX2400