Rotate around the center of a CCLabelTTF as achnor point

Rotate around the center of a CCLabelTTF as achnor point

I want to rotate a CCLabelTTF around it's center.
But it doesn't look like it. It does look more like a rotation at the
bottom of the CCLabelTTF.
Code:
CCLabelTTF *aLabel ... init/addChild and so on
aLabel.string = @"0";
aLabel.anchorPoint = ccp(0.5f, 0.5f);
[aLabel runAction:rotateLabelA];
How to rotate a letter around its visible center, if it is a CCLabelTTF?