I'm being badgered by a friend who insists that the "Pleiades conjunction" which allegedly will occur on May 20th, 2012 is "proof" that the Mayans could predict at least partial solar eclipses. The "Pleiades conjunction" she is talking about is when the Earth is on a line drawn between the Sun and the Pleiades cluster.
Naturally "dumb luck" has been my answer, that the Mayans predicted one event and that everyone is attempting to tack on another event which the Mayans did not predict to the Pleiades conjunction, but its to no avail.
Personally I'm hoping that someone with better astronomy knowledge than I will come up with a point, similar to the Earth never being in "conjunction" with the "Galactic Core" because Earth's orbit being 5-1/2 degrees off the "Galactic Core", to explain away the concept of a Pleiades conjunction.