Another one of my dumb questions...it seems no matter what program we try to print out of (to an HP Photosmart printer) from our Mac pro, there seems to be a default page setting of an index card. So, unless you remember to reset the page each time, you get a pile of paper with a 3x5 section printed in one corner. I've looked everywhere for the culprit and can't find it. Any ideas where I look to return this to "US Letter"?