When I first installed Firefox on my HTC EVO Design, zoom,worked. it stepped working after updating., How can,I,fix,it?
Try getting the complete installer for the latest version, then uninstalling the present one (but leave the profile alone) and then installing the new one.
Uninstalling on Firefox for Android will remove the user profile.
Zoom only works on desktop sites. On most mobile sites the site author sets a preference to disallow zooming. Firefox for Android will respect that preference.