I expected this to happen so trained myself to always keep in mind whether typing in the upper or lower box.

Consider yourself lucky you weren't typing a large catch order. Imagine someone wanting to type "Buy 8000 BTC if price falls to 8" and actually inputting "Sell 8000 BTC limit 8".

This is a major interface flaw of Mt. Gox. I consider it so dangerous that I warn people I execute trades for that the mistake might happen to me one day. Even though I know of it, when speedily inputting orders on a small screen, the mistake is just very likely. In the end, Mt. Gox is ghetto, we all know that. Be happy as long as they figure out why their trading engine displays impossible spikes.

So basically... I bought for $14.23, Sold at $14.18, then re-bought at $14.05.

I'm right back where I started (a little ahead tho)

I once made an order to buy 1000 at 0.0199 but accidentally sold. it just sold for the highest bid though

Just moved like .208 or some odd number a couple of days ago.  I hate the fucked up numbers, and I accidentally sent something to the wrong place and now I've given up trying to fix at the moment lol.   Gox and even Tradehill could use some visual changes to the site to make things clearer, but I guess it's nice that there is tons of user error going on and Gox isn't the only one messing up his numbers :p

They don't. In any case, Confirmation Dialogs are considered by many to be a nuisance only. They are usually just clicked away by experienced users.

Same thing happened to me.  I sold ~20 BTC a few cents under my buy while setting up some step orders.  The loss was small but I did the same damn thing again later in the day.  

I really shouldn't drink and trade.  

Lucky enough not to have that issue because when I buy I'm spending every MTGUSD I have so it always requires a calculation to see how much BTC it is.  Selling doesn't require that(Pick your price, and amount of coins and done).