2001 Rear Firestone GTA's "cupping"

[bluewagon]

I am an investigative writer soliciting information about any 2000/2001 Focus owners who are or who have experienced "cupping" on the rear tires.
This condition, also known as "scalloping" exhibits itself as uneven tread wear both across and around the tires. This eventually causes a rumbling sound from the rear wheels.
I’m investigating whether or not this condition is might be related to the “rear bearing” recall that affected the 2000 model year. Ford says the problem is due to lack of owner tire rotation. Firestone says the problem is with the rear suspension. What do you think?
If you have, or have had this problem, please let me know, either on this message board, or via email (pndxtr1@aol.com). I need specific year, model, and mileage information, tire information, and what you and your Ford (or Firestone) dealer have done to resolve the problem. You may include names, if you wish (dealer and/or yours), but this name information will NOT be used without your written permission. I am interested more in facts than in identities.