Who can tell me what about the infamous Shimmy? Since I can't do a search I resort to asking.

Here is my story...
I developed a shimmy after I rotated my tires. Rotation cause, who knows... So I take the Maxima to the dealer. Later I get a call stating my rotors were warped, which they replaced since the car was under 12K miles. They did an 4 wheel alignment and balanced the tires. All free to me because if this 12K mile thing... Anyway the brake shimmy went away, as a result of having new rotors and pads, but I still get a 50 mph thru 75 mph wheel shimmy. Enough shimmy where my watch rattles on my wrist when driving. 50% of the problem has been fixed I believe, but now they need to finish fixing it. Tonight I dropped the Maxima off again at the dealer, 2nd time in a week, and still under the 12K mile mark - fact is it's I’m right at 11,800 mile mark <sigh>.

What are some of the reasons and cures to fixing this problem. Has anyone had experience with the dealer that successfully cured the problem, or will this be something I have to deal with until the end of time.