asterisk users - Nov 2006 - zaptel, bristuff zaphfc, and florz question

Hi,

We've been using zaphfc single ISDN cards as cheap Zaptel timing
sources for our Asterisk boxes for a long time, and in the asterisk
1.0.x series, had zero problems doing so.

I now have some boxes with Zaptel 1.2.x (with a mixture of 1.0.x
asterisk and 1.2.x asterisk), and this setup no-longer seems stable -
By plugging or unplugging the ISDN cable, and sometimes just randomly
the card will start spewing buffer over/underring errors.

I already knew about the florz patch, and I have to say that this
makes a HUGE difference - It seems to stabilise things to the point
where it will run for a week, but does still go mouldy after a while
with a constant stream of:

Nov 16 15:54:01 pabx kernel: zaphfc[0]: b channel buffer overflow: 854, 854
Nov 16 15:54:05 pabx kernel: zaphfc[0]: b channel buffer underrun: 0, 0
Nov 16 15:54:05 pabx kernel: zaphfc[0]: b channel buffer overflow: 446, 446
Nov 16 15:54:06 pabx kernel: zaphfc[0]: b channel buffer overflow: 855, 855
Nov 16 15:54:06 pabx kernel: zaphfc[0]: b channel buffer underrun: 0, 0

This leaves the box sufficiently ill that a power-down is the only way
to recover.

Can anyone offer any pointers? Is there an alternative but equally
cheap hardware Zaptel timing source out there perhaps? Preferably one
which offers a single ISDN2e port :)

P.S. Restarting Asterisk and/or Zaptel every night is not a good
answer except from a Windows administrator :)

Thanks
Steve

Replying to myself with one further piece of information - In the most
recent log, the otherwise stable florz version of the driver seems to
have died with this message:

Nov 16 15:48:34 pabx kernel: zaphfc[0]: empty HDLC frame received.

Might this mean something to someone?

Thanks again,
Steve