Pages 8.2 Default paper size reverts to Index card 8.5x11

No matter what I do, the default paper size for a Pages doc is Index Card 8.5x11. I have set the printer default paper to Letter 8.5x11 in System Preferences, and it is always to that setting when I check. Where the problem seems to be is in the Document tab in the Inspector (if that's what it's still called), where it is always the Index Card setting. Thus, when I print with my HP printer and set it to two-sided, it always warns me about the Index Card paper. When I check the settings on the HP in the print box, the paper type and size are plain paper, US Letter. Even when I change it to U.S. letter in the Document tab in Pages, when I go to print, I still get the warning about it being set to Index Card 8.5x11. Anything else I can do? It's more of an annoyance than anything, because everything prints just fine after I click the Continue button.