Distorting Blocks

[voodooboy]

I am trying to find a tutorial on the distorting transitions. You know the ones I mean, the blocks of color that distort from one side to the other, sometimes with straight sides and sometimes they bow in or out to expose an image or fill a space for copy.

I have tried doing this with "Shape Tweening" and everytime I do more than one transition in a layer, the block of color rotates on me.

Any help would be greatly appreciated.