[TenTec] need help getting a Pegasus up and running

[yash at aol.com]

 Using the TT software from the TT down load site.  Computer is xp with sp-3 and 4 gig of ram. Software loads fine on computer. Using a usb to serial cable,which on the device controller says its in place and working fine and is set on com 3. I went into the TT software and changed from com1 to com3 . turned on the Pegasus and started the software the two could not communicate with each other. tried all 6 different com port settings ,nothing changes. re loaded the TT software ,no change. What about the Baud rate and priority stuff,make a difference? could find no where the TT requirements for rates etc. 
     I just got this Pegasus, was told it worked fine ...don't they all say that... I will buy the N4PY software as soon as I make sure the basic Pegasus is working ok. But need to get it up and on line with what I have.

Maybe the usb/serial cable a bad thing??
can put a serial card in if needed . 

Sure would be grateful for any help on this. After using a flex 5000 and power sdr   for 4 years,thought the little Pegasus would be a no brainier.
Thanks
dale wt4t