UnMHT has suddenly stopped working. Command suddenly and simply disappeared from the pull down file command menu. Tried the obvious: restart computer, restart Firefox, reinstall UnMHT, reinstall Firefox, etc. Add-on's says that it's installed and running, and no, I haven't switched off something, at least not knowngly; it remains in the default setting. This is an add-on that I use *constantly*. Have installed Mozilla Archive Format as an alternative to keep up the pace but would much rather be using the UnMHT. Win XP Pro 32 Bit system by the way. (Hey, it's stable!) Computer on 24/7 Full up AVG security. No security alerts before it happened. It just disappeared from the pull down file commands menu. Literally one minute it's there, and the next it's not. Is this some new glitch related to XP? Never seen anything like this before. All help and suggestions greatly appreciated. Thanks! VicB3