I find align to pixel grid does not play nice with the traditional grid. Seledct all your itmes adn turn off align to pixel grid. SInce you set up your grid to be 20 pixels, then using teh traditionl align to grid shoudl work the saem, you just need to make sure thet width adn height of your objects is a whole number in pixels.
Hey Andrej. You actually have to turn off pixel preview. Then you can turn on 'snap to grid' (as opposed to 'snap to pixel' - which doesn't snap to the grid at all). Then you can zoom out and do your layouts quickly.
This took me a while to track down as I do the same thing. That's an annoying snapping thing with Illustrator. 1 of MANY, heheh.
Hope that helps.
Fictional UI Design for film and television