> I recently added a USB PCI  board to my Mac and attached a USB 
> printer to it. The printer works fine but some, not all FB
> applications produce a dialog that says

1.
What kind of Printer
If it is HP DeskJet970Cxi or other 900 series printer,
it is something wrong.

Even with PBG3/400 built-in USB does not work,
I often see similar error messages with other application.

2.
Please look at compatibility list of PCI board.
Some USB card may have problems.

Masa