I don't think that show with Tony Robinson was as conclusive as you think, Brutus. I watched it and what I got out of it was basically they went through the list of controversial statements of "fact" in the book and then set about asking Christian scholars and various people on the street to refute them. The only "fact" actually disproven is the one about the modern Priory of Sion, which is acknowledged as a hoax. But when it comes down to things like Mary being married to Jesus, the show relied upon Church officials basically saying "no, the Bible doesn't say that and the Bible is the definitive source" or things to that effect. In the case of Mary coming to southern France, they interviewed people there who agreed with the legend, but when asked if they thought Mary brought Jesus' offspring with her, it was all "no that would be heresy" and similar things. Frankly, interviewing the man on the street for his opinion does not constitute proving something wrong; nor does interviewing Church officials who conveniently seem to forget that their own church once held similar views, in the writings of Hippolytus and Origen. The arguments on the Da Vinci Code side are no less unsupported than the people who think "because God said so in the Bible" makes a decent statement of fact.