I was told to upgrade the firmware to resolve. Unfortunately, I downloaded of the firmware upgrade, but it complains of a missing file when I try to install.
Numerous e-mails to support at Dell that prompt insulting responses to reattempt the same steps that have not worked in six attempts on two computers. It's a sad but obvious conclusion for me, a Dell fan, but the support folks don't read the messages or don't care.

Good Luck,
Splash

I am having the same problem. Dell has sent me a new 960, but it has the same problem- it won't automatically receive faxes when set to the receive"when fax tone detected" mode. The tech staff is of no help at all. They have bounced me to the wrong areas several times. After two frustrating hours on the phone with them Saturday, they gave me a new 800 number which would connect me to the "real" experts on faxes. When I called it, the line rings once and goes dead. My friend told me not to buy a Dell because the support was so bad, and now I've learned that lesson the hard way.. If anyone out there has an answer, please let me know.