Why are Bitcoin prices so different between different markets? Sorry if this is a basic question, I'm new to this stuff.

Currently, according to cryptocoincharts.info, Bitcoins are trading at $1050 on BTC-E but $1228 on Mt. Gox. How is this possible? What would cause such a large price discrepancy? Shouldn't it be possible to capitalize on this difference by buying at BTC-E and selling at Mt. Gox, and if so shouldn't that tend to equalize the trading prices?
Mtgox has dollar withdrawal problems. So a dollar within Mt. Gox is worth (valued) less. So you pay more dollars and take your bitcoins out, hence the higher exchange rate.