I have been trying around with Crows GMap Generator, and Ricks. Although, I could not find a way to make a 2x2 or a 3x3 GMap. I have tried on ricks, and all I get is this:
It will generate a 2x2 fine. You're probably using a center x/y outside of the bounds of the GMAP. If it's a 2x2, a center level at the default (5, 5) won't work.