Zoom modem troubles

[Douglas E Thompson <dt2k+@andrew.cmu.edu>]

I just got a Zoom 14,400 baud modem for my IIgs.
The only problem is, it won't download at speeds over 2400 baud.
It works just fine uploading at any speed, but won't download.
I have the correct cable for high speed modeming, so that's not the problem.
I think it must be either a problem with the ProTERM v3.1 modem driver that I'm using, the init string for the modem, or some of the settings in the modem port control panel.
If anybody out there has any ideas on how to fix this problem, PLEASE reply, because without downloading capabilities, there is hardly any reason to have a modem.
Thanks in advance,

Doug Thompson
(dt2k@andrew.cmu.edu)