Hello Richard,
I haven't found a way to turn this message off but you can bypass it. While it does belong to the UFRII Backgrounder service, and this is located in your Login items, removing it from here only stops the service starting when you log in. The second you select to print using the UFR2 driver, the message will appear again.
So, the trick is to make a preset with the setting mentioned selected. With an application open, select to print the current document. Then change the print menu to Quality menu and press the Quality Settings button. The next pane will show the Graphics Mode set to 'UFR II Mode'. Change this to 'Raster Mode' and OK. Now, open the Presets menu and select Save As. Give it a name, like Raster, and choose for this printer only. Save this and print. You should find that the message will not appear now and every time you do print just ensure this preset is selected.
Pahu