I had this wobble, too! It looks like the entire case (esp. the aluminum) may have warped. The way I fixed it was -- and I kid you not -- by bending the entire keyboard ever so slightly so that it doesn't wobble anymore when placed flat on my table. I suspect this is what beanaroo meant by "corrected it with some care"! I really wouldn't suggest doing this yourself unless you really know what you're doing.