Was unable to change cartridges because cartridge carrier would not move to the middle section. Called tech support and tech was unable to pin point the cause . After some 35 minutes on phone , and a promise to E-mail me , I rang off and then decided to try re-install process , as provided at initial hook-up .. After install procedure , was able to get correction of installing ... Would seem to be a possible electronic glitch ?? You can call me at 435 - 632-**** for details . thanks icon and replace empties .