Audio problem: Right after Max and Tom watch the two fake snuff films, Max mentions the record company's lack of interest. At one point his lip movements don't seem to match his words. (00:50:35)
Audio problem: When Machine's mom was telling him she'd really hope he'd go to church with her tonight, her mouth was saying something completely different.
Answer: A snuff film is a movie where someone is actually killed on film, where the intention is to sell the movie afterwards. There are several other instanses where people are shown murdered on film (news reports, the Zapruder film, dictatorships documenting executions, etc.), but if the purpose of making the movie is not commercial, it is not a geniune "snuff" film. FBI experts and other law agencies state that they have never seen a genuine "snuff", and that it is most likely just a rumor, especially since the concept of someone willingly selling evidence of their own crimes to strangers and remaining undetected for 30 years, is highly unlikely. See http://www.straightdope.com/classics/a5_258.html for more details.
Twotall