Can't disable Anti-Aliasing with glDisable.

I’ve created a glx visual with the following attribute list:

	static int attrListAntiAliasing[] = { GLX_RGBA, GLX_DOUBLEBUFFER,
	    GLX_RED_SIZE, 8,
	    GLX_GREEN_SIZE, 8,
	    GLX_BLUE_SIZE, 8,
	    GLX_ALPHA_SIZE, 8,
	    GLX_DEPTH_SIZE, 16,
	    GLX_SAMPLE_BUFFERS_ARB, 1,
	    GLX_SAMPLES_ARB, 4,
	    None };

Anti-Aliasing is working fine, but unfortunately I can’t turn it off with

glDisable(GL_MULTISAMPLE_ARB);

It’s just always on. On Windows it does work though.
Did I forgot something? How can I toggle Anti-Aliasing?

I’m sorry. I made a mistake at another part of my application, which caused the glDisable line to be never executed. Now it’s working fine.