Fox News has a reputation for being rather slip-shod when it comes to fact-checking, it's unsurprising that they got the wrong birthday. As for the spelling of his name, it boils down to different ways of translating Arabic script into the English alphabet (witness various spellings of the Islamic holy text - Koran, Qur'an, Kuran, and Curan). "Osama" is the most commonly used spelling, and I'd just as soon go with the BBC spelling rather than FOX's.