Problems Using Edirol Um-1sx, Driver fails to load Options

Hello,

For the first time ever I am trying to hook up a MIDI device (in this case an Alesis QS8.1) to my Power Mac G5. I purchased an Edirol UM-1SX interface and followed the instructions precisely on how to install the driver (not that there's much to follow...it's a simple pkg installer).

Unfortunately, the moment I try to plug my MIDI interface into the USB port (after rebooting of course) I get an error dialog from the OS:

"System extension cannot be used.
The system extension "/System/Library/Extensions/RDUSB0009Dev.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update."

Well then. Lovely. The driver is the latest download from Edirol's website (v1.1.1). I submitted a tech support question to Edirol and they just told me to re-install the driver, which I've done countless times now following their instructions explicity. I always get the dialog and the system does not recognize the MIDI input.

Has anyone seen this problem and know how to resolve it? Is anyone out there successfully using the UM-1SX under Mac OS X Panther (10.3.3)?

Thanks,
Scott