Server 2003 Fax won't send faxes, always reports Busy signal

Ok, Windows Server 2003 (2 gb ram, 3.2ghz proc., raid1 120gb, 56k modem).  We've installed the fax service, and for over a year, it's worked great.  After a brief power "blip" in the building last week, the fax service no longer works...at least, not correctly.  

We sent out a mass-fax (137 recipients) and as it dials each number, it reports that it's busy...every single number.  I got suspicious and called a few, and sure enough, i get rings...no busy signal.  Anyway, i suspect the fax service is corrupted, so I uninstall Fax and reinstall it.  I sent a fax from the server to our local phone number, and Voila!, it works.  

I then try sending it to all 137 fax numbers and it locks goes back to it's old habit of reporting every number to be busy.  

As I type this, I suspect the modem could have gone bad from the power "blip" last week, but I haven't changed it out yet.  However, since it did work to one fax number, I guess I'm not 100% sure it's a hardware problem.  After getting the busy signal w/ the mass-fax, i tried just 1 number and it didn't work either, so it's not a "quantity of phone numbers" problem.  

Any suggestions?