A number of years ago, Epson was faced with costly litigation surrounding its practice of designing ink cartridges that reported an empty status long before the cartridge was out of ink.  Apparently this practice hasn't stopped; printers are stll "lying" about ink and toner levels.  (Christopher Null, Your printer is lying to you (August 24, 2008) tech.yahoo.com.)  Fortunately, there are things you can do to get at all of the ink or toner you bought (other than file another class action lawsuit).  (Farhad Manjoo, Take That, Stupid Printer (August 21, 2008) www.slate.com.)  One piece of advice is to "Google some combination of your printer's model number and the words toner, override, cheap, and perhaps lying bastards."  Now that's useful advice.