I don't know why, Keith, but "Eaton" seems to be a more common spelling for proper names in the U.S. and Canada - so we might be likely to spell the school's name that way, too. Most of the time, the extraneous vowels are on your side of the ocean - but "Eaton/Eton" is one exception to that rule. A Google search will bring up the Eton Boating Song under either spelling (but more commonly under "Eton"). When I post things that I want people to find in searches, I sometimes include common misspellings as alternates.
-Joe Offer-