PowerMac G4 USB-Serial & ADTPro

I have a PowerMac G4 that I have set up with Mac OSX Tiger. I hooked up a IOGear GUC 232A, and tried using ADTPro to my AIIe Enhanced. It will download the bootstrapper fine, but then the AII just hangs. It is like the G4 isn't seeing the AII's requests after it loads the bootstrapper. The same setup works on a Windows PC with XP. I've tried 2 of the adapters, and my super serial II card is set to terminal, so I don't need a null cable. Like I said, it works fine with a windows xp machine. The driver I downloaded says it is for an intel mac, and mine is a powerpc, but the mac recognizes the adapter, and I was unable to find a driver that states it is for a powerpc. Anyone else using this setup? I can do what I want with the windows pc, but would rather use the MAC. Thanks.