Hi Tonisings,
I have a few questions:
1. Do you fax to a variety of places or mainly to one particular fax number?
2. Have you adjusted the fax speed setting in the printer? The default speed has been lowered to improve compatibility with VoIP phone lines.
3. Do the faxes still go through, just taking longer?
4. How is the quality of the received faxes?
You might try turning off ECM as error correcing mode can cause the fax to try resending data.