Photoshop: Please stop selecting the previous layer when I do a "Step Backwards"

I am REALLY sick of after chosing a layer, making a brushstroke that isn't quite right, clicking "Step Backward" (alt-ctrl-z) AND PHOTOSHOP AUTOMATICALLY SELECTS THE LAST LAYER I WAS ON. This has cost me countless hours of drawing directly on the background layer. I have my Wacom pen set to "Step Backward" because I want to have more than one level of undo, but because it selects the previous layer, unless I am being really careful, I end up drawing on the wrong layer. Usually, I have had to learn to select a layer, choose the eraser tool, then pretend to erase something, just so that if I have to step backward it won't select my previous layer. If this has been addressed, great, but I keep thinking it will be, and cannot believe that by CS5 it's still happening.