| 4345s dont like digital lines
Very much at all. I've the same issue on several deployed machines. Flashed firmware to current versions.....no joy.
The issue is VOIP and how less and less true Analog lines are being used every day. Some of the older machines and most Brothers use a hardware modem, and not a host-based modem, so they work better.
Good luck - you might end up having to replace that monster.
Have you thought about utilizing the "fax to email" function instead? | 
Linear Mode
