WinXP Home Faxing and WinFax Problem

Customer has WinXP Home edition – all current updates done. With either builtin fax support or with WinFax 10.02u the machine will comfortably accept the first fax. When a second fax comes in the computer attempts to answer but the connection is never made.

Have uninstalled/re-installed the software; the modem drivers (HCF modem) redone the default setups; tried all the suggestions in the symantec FAQ with no success.

My hunch is that it is in the WindowsXP software but not sure what to try next!!

Open to any help and suggestions.

Thanks

Al