It's spelt with an a, like caesium, paedophile and probably a variety of other words. Or more rather, it's technically accepted as being spelt both ways due to each being accepted in different places.

Why is it that Americans think our way is the only correct way to spell things, yet everyone in the UK and such seems to be perfectly fine with and knowledgeable of American English spellings and whatnot? It's shameful. You're all making us out to be ignorant, pompous jackasses, and then we wonder why other countries hate us. It's because we generally tend to act like our way is the only correct way.

We're fine with you having your own way of spelling things so long as you allow us to continue spelling things our way. :) Or maybe that's just me? However chances are that it's because there's more people in America than the UK, which means that people in the UK are more likely to be familiar with American spelling whereas people in America are less likely to have come across UK spelling? Just a thought. Though I do agree with you.

You might be right, Cinn. Maybe it's also because there are more Americans around to act like assholes. We aren't exactly known for being polite...