Unbalanced wheels?

[Horace K. Sawyer]

My number one nemesis!  Can be bad tires.  Can be bad wheel(s).  More 
likely, one of your wheels is slightly out of round.  Could be a flat spot 
on the *inside* where you won't notice it.
2 months ago, I had an *unsolvable* balancing problem on a brand new 
vehicle.  Michelin LTX tires.  One of the tires turned out to be bad.  Even 
Michelin can screw up.  Problem is *proving* this.  But after 6 different 
balancing attempts, they began replacing tires.
If the tires are well worn already, they may not balance out properly no 
matter what.  I believe I am correct on this.  What type and size 
tires?  Be interesting to see if the problem goes away with new 
tires.  Also, the balancing machine is a very good way to determine if you 
have a wheel out of round.
Good luck
HK