QTR-Quadtone RIP

I am running a G5 dual 2.5 with an Epson 4000 usb printer hooked up to it. Prior to the 
Leopard upgrade printing in Quadtone worked fine. Haven't printed a lot, but it worked 
like a charm when I did. 

After the upgrade though, the printer queue starts up and then immediately quits. The 
standard Apple Problem report window comes up showing:

(after some system info)

Dyld Error Message:
   Symbol not found: _CPLServerRegisterListener
   Referenced from: 
/Users/warren/Library/Printers/Quad4000.app/Contents/MacOS/PrinterProxy
   Expected in: /System/Library/Frameworks/Carbon.framework/Version/A/Carbon

Have chatted some with Roy about this, have reinstalled the OS at his suggestion, and still 
no Quadtone printing. Any "deep Mac" users out there, that might be able to diagnose this 
system problem?

As the "Carbon" in that last line is a binary file, I can't see where exactly the _CPL... is 
supposed to go, or if I can grab it from other machines I have here. Or, is it simply not 
part of this PPC (native) system?