Done the ******* thing. And can get to 2048 (or very close) most times now. There's a trick to it, there always is. Took me long enough to find the b'stard though, because, well, I'm stupid. Use the left, right and up arrows. Never touch the down arrow. Unless you balls it up for yourself, you'll get there just about every time.
I was just going to call the other Jay all the names under the sun for posting this in here in the first place, but your technique got me to 1024 before I buggered it up, so I reckon its a winner. Was just about to throw the computer out of the window as well!