Color Laser Printer; Canon LBP7660C, UFR II driver. Windows 10 version 1607, build 14393.1066 (& the 5 or 6 prior to that) Firefox v53.0 (& about the dozen before that). ONLY Firefox, ALL other Windows 10 applications print correctly. Have attempted all of the work arounds and suggestions, removing, reinstalling, totally purging all of Firefox, etc. 1) Ignores which tray to draw paper or envelopes from; always only wants the manual feed tray 2) Incorrectly scales printed objects & pages. For example, a return label from Amazon is printed about 1/4 the actual size. A web page is between 1/3 to 1/5 its actual size. An airline boarding pass (United, American, & Delta) is about 1//4 the correct size. 3) Ignores all graphics scale setting in the printer driver setup 4) Ignores settings for color/black & white/grayscale 5) Ignores settings for printing on one or two sides, always only prints on one side And several more printing related issues. Also incorrectly scales anything printed to Adobe Acrobat X, when opened & printed through Firefox, when opened from Acrobat directly, prints correctly. ONLY Firefox. No other application has any of these issues. Any help appreciated. Thanks