LaserWriter 12/640 print problem at high altitudes

Dan Jahn writes: "We just bought and setup an Apple LaserWriter 12/640 PS Plus. About eight out of ten prints has these strange bubbles that print along the left side of the page. After discussions with Apple, it turns out that this is a known problem at high altitude (we are at 6500 feet). Apple will not take back the printer, nor will MacZone, because Apple will not issue an RMA."