Gui.SelectionGrid, too few buttons?

    var levelGridInt : int = 0;
var levelGridStrings : String[] = ["Cubic Flatts", "Blank Test", "Blank Test 2", "Blank Test 3"];

On Gui...

levelGridInt = GUI.SelectionGrid (Rect (Screen.width *.33 +3, 20, Screen.width *.2 -5, Screen.height *.1), levelGridInt, levelGridStrings, 1);

The problem is, I never see "Blank test 3". I've only seen one other similar problem to this, and his solution didn't work out for me. I have to assume it's human error in the code, some where, but I don't know where I went wrong.

The code you posted works for me without modification, using the default skin, running in the Game View in the Unity 3.0 editor.

It appears some external factor is contributing to your problem (version of Unity, GUI skin, screen size, platform, or surrounding code that you did not include in your question.)