Note: these problems started recently without changing anything in FFox. Examples: HomeDepot.com: "sort by" feature stopped working. Also cannot change number of listing per page. USPS.com: could not print shipping label. Instead of a PDF label popping up, I was prompted to save as or open with "com.usps.cns.web.pdf.labelgeneration servlet". USPS told me to remove everything after ".pdf" Another site (can't remember which): after filling out a form, pressing "submit" did nothing. So I: Turned off Adblock extension Disabled NoScript extension Updated JAVA to the latest version Tested w/ Opera, same problem Tested w/ IE, worked but now my hands feel dirty!