I hope it can fixed some day. You can use Homescreen Designer to move all your icons to the right side of the screen on landscape mode. It's the icons on the left edge that gets overlaped by the dock icons. However, I believe you have the same amount icons as in your portrait... or the icons gets shifted around going from portrait to landscape and the other way around.
I try to keep my widgets on top now... so it looks cleaner on landscape. I photoshop my dock to the wallpaper now because don't like what the dock does in landscape mode when activated in WB.
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