IE 7 does not, repeat not, resize pixel-sized text. It partly compensates for that by allowing the user to scale/zoom the entire page, including images (which quickly leads to massive horizontal scrolling because of its bad implementation). But if you choose “Page/Text Size” from the menu to change the text size, nothing happens if it has been sized in pixels or an absolute unit (points, millimeters, centimeters, inches, or picas).