Hello, my name is John and I've had a case of the wobbles for 3+ years.
Went through some possible causes;
> speedo cable broke, thought maybe a cable bit had become lodged on front axel house & caused damage (nope)
> steering head bearing had a "flat spot", when on the lift, handlebars would "settle" into straight ahead position. Replaced bearing (nope)
> put in higher weight fork oil (20w?) (nope)
> new front tire two year ago(nope)
> new front tire July 2007, Avon Venom. Wobble is gone

, which makes me wonder if the previous tire replacement was done correctly??????
I realize a number of things, or combination thereof can cause this. But in my case, the front tire seemed to be the culprit.
jh