Kbase Article of the Week: Mac OS X 10.5.5: USB Connected Printers do not Print; Printer Queue Displays “Printer is currently off-line” »

Apple Support:

After updating to Mac OS X 10.5.5, you may not be able to print to some USB-based printers. This message may appear in the printer queue: “Printer is currently off-line.”

I remember this bug showing up at a couple of schools I supported back when I was a full-time Mac consultant and it suuuuuucked.