Anyone use IAXmodem with Hylafax and Asterisk?

[Tagg McDonald]

i am trying to setup some faxing over our VoIP system. so far i can send 
faxes like a champ, i can also receive faxes send from my box out to the 
VoIP provider and back into our system. but i can not get the darn thing 
to receive faxes from other fax machine.
if anyone has played with a setup like this and might have some insight 
let me know.