Concerning the low toner issue with an HP 4000 (noted here yesterday):
Mark Bogdanoff suggests: "The document will print if the misleading message is ignored. The option to continue does not appear, but if ignored, the alert will go away, and the document will print.
Derek Rawson adds: "This is also the case printing to my Epson 680. Where, under OS 9, I could use the ink cartridges until they were empty, with OS X I get a warning dialog as soon as the ink light begins flashing that insists that I change the cartridge or stop/delete the print job."
Justin Beek adds: "We had an Xante with the same problem. A couple of suggestions:
Ignore it and it will print anyway. However, the alert box pops up on every page!
Turn off the 'Soft Errors' from the printer. On our printer, this disabled the low toner or low paper alert boxes. I did a quick search and found this HP page. It might have info on how to turn this off on an HP.
Ken Beck suggests: "As with my old Laser Writer, I simply remove the toner cartridge, give it a few taps with my hand do shake the toner, replace it in the printer, and alls well."