GIMP :: Simple Text Box - Square Image With A Letter On It?

I just need a square image with a letter on it. Here is what I have done:

1) File - new. 256x256. OK.
2) Click the 'A' button in the toolbox
3) Click 'Use Editor (since nothing seems to work)
4) Drag a rectangle onto my image.
5) Click on the editor
6) Type the letter 'x'

Guess what happens? Absolutely NOTHING! If I type other random letters, the editor disappears. What am I doing wrong? (and why is this so difficult?).