I have to report that I always believed the confusion over Jimmy Wales' birthdate to be a covert and ingenious attempt to demonstrate to the community the need to use the facts given in reliable sources, and not to prefer what might be honestly expressed views but which are not supported by reliable sources. Perhaps I may have too conspiratorial a mind.
Nevertheless, there are similar disputes for other articles. See the biography of the great playwright Sir Terence Rattigan for a case where the date of birth is also in dispute to the tune of one day, and where reliable sources are in disagreement: http://en.wikipedia.org/wiki/Terence_Rattigan
I had to deal with a case where the dispute was over a year, where it is possible to guess at which date is the more likely: http://en.wikipedia.org/wiki/Emlyn_Garner_Evans