ZTerm and USB to serial problem

I need help. I am trying to get ZTerm to recognize a USB to serial (DB9) connection and am failing miserably in doing so. I suspect it is a driver problem, but I can't find drivers online. What I am connecting to is a satelite TV receiver (FTA - Coolsat).

Any suggestions? All help will be rewarded by years of gratitude.

G4PPC; 1.25 GHz; OSX 10.4
IBookG4; 1.33 GHz; OSX 10.5

Thx,

*Moved thread to appropriate forum - Question not on OS X itself but on Applications*