Fax Detect & calls on one FXO - working but not working


I have a PIAF purple box,

PBX in a Flash Version =
FreePBX Version =
Running Asterisk Version =
Asterisk Source Version =
Dahdi Source Version =
Libpri Source Version = 1.4.12
Operating System = CentOS release 5.7 (Final)
Kernel Version = 2.6.18-274.3.1.el5 - 32 Bit

I have faxes working using Hylafax + Avantfax, I also installed the 1 free fax for asterisk license from Digium.

There is one FXO for calls and faxes. I have both working but the faxes are only detected when I force the call into the hylafax custom destination.

The fax detect is configured on the inbound route.

I tried the work around using the IVR mentioned here http://pbxinaflash.com/forum/showthread.php?t=10565
Sometimes it detects the faxes but very rarely.

Is there any config that works using the one line for calls and faxes?

Thanks, Joe