Fax receiving problem


I have an AAH2.2 box with an ISDN HFC-based card. I use the bristuff support for the ISDN card and everything is ok except for incoming faxes that are not detected.

While I can send faxes, I cannot receive any even when the fax machine is set for the incoming calls extension.

I already run AAH2.2 with PSTN and there is no problem with incoming or outgoing faxes. I am convinced the problem is related to ISDN or the particular driver in use.

Does anybody know, if something related to ISDN should be configured in order to resolve this problem.

Any help is greatly appreciated,