Truly ESSENTiAL Add-On BUT has Titling Problems Rated 5 out of 5 stars
MHT & Faitfhul Save does have one problem regarding character substitution in the save-as file title, but that failing aside, it's a truly MUST HAVE for NE1 who saves webpages - which is most of us, and i.m.h.o.'it' should be built in to the basic Firefox program.
MHT&FS v2.0.5 and earlier versions DON'T appear to follow Intrnt.Explr convention regarding CHANGing DOTS - and perhaps some other special characters, in a file title TO an UNDERSCORE "_".
For example: if a web-pages title is "Blah blah version 3.0.1 blah.mht", then I.E. will save as "Blah blah version 3_0_1 blah.mht" MHT&FS may save as "Blah blah version 3_0.1 blah.mhtml" or, it MAY not change the dot characters at all.
4_5 out of 5 Stars from me. Currently using Vista Sp2 & Firefox 3.6.28