I have been using my Korg X5 with a Windows laptop for some time.  Now I am stuck in trying to connect it to my MacPowerbook.  Since the Mac does not have a built in serial port, I bougth a USB-Serial Port converter and connected the cables to the X5 PCInterface.  I have installed the Korg PCDriver in the Mac:System:Extensions Folder.  I have tried to connect by using the MacVersion of Korg Editor, choosing the Printer Connection - no result. 
What am I missing?