Yes pause has been tried.
LCR is not used.
Customer has not change providers
All numbers are manually dialed.
The work around for now is the customer pushing the off hook button, dialing the number, wait for the other fax to answer and than push start.

The more I think of it the more I feel the problem is in the IPK II.

We stumped NEC NTAC, their suggestions.
1. remove SLI card in programming and than re-slot it. This did not clear up the problem.

Switch out the SLI, upgrade software, have not done these two yet.
And last switch out the CPU.

Keep asking the questions. It does help to shed light on the subject.

We get old too soon, smart too late