Do a little search and you will find a solution.
Oh wait a minute...i've done it for you...here you go.
http://www.team-bhp.com/forum/tyre-a...oy-wheels.html (Solution for vibrations after installing alloy wheels)
BTW it was the third thread under yours in the same section that you posted.
Man the things i do these days...do a little search before you get key-happy with the keyboard...it generally works wonders.
Drifter