I got firefox to remember passwords for a couple sites that were blocking autofill. It involved opening up the xml file where passwords are stored, copying the latest entry, changing the url and ID number, then opening up the password manager in firefox and updating the actual password there since the XML file only stores an encrypted version. It wouldn't autofill instantly, had to click on the username box to get it to work but it saved me a lot of time from entering a massive password that system required.