Why do settings such as paper size and print quality change from time to time?

By default, only the combinations of paper size, paper type, and print quality that give you the best results are displayed in the Print Pictures dialog box.

You can turn off this safeguard to see all the options and combinations, even if they might not print well. To do it, click Options on the lower-right corner of the Print Pictures dialog box, and then clear the Only show options that are compatible with my printer check box.