High Failure rate on faxing

Hi Guys!

Hope you can advise

We are running Asterisk 1.2.4, SpanDSP 0.0.2pre25 on a P3Ghz, with QUAD E1 Digium Cards T4xxp driver.

Clocked as follows Port 1: Clocked from PSTN network, 2-4 clocked as slaves.

Typically, on a fax run of 1000 faxes we will experiance around 60% failure rate. Our CDRs are reporting that the last application was TXFax on all failed faxes, wheres HANGUP is reported on all good sends. The DATA is good - its all opt-in fax data.

I am stumped as to why we are getting such a high failure rate: The failed calls are failing after 30 seconds or so ( i gues some sort of autonegotion issues? )…

We are running on On-Net E1s, approx 25 foot from a main MCI/VERIZON switch. Could GAINS be an issue here?

Any help much appreciated.