Tires: cupping on rear tire, wheel alignment, wheel hub

Question
I have a 2002 Prism that I bought in 2004.  When I bought it there was a vibration sound coming from the right rear tire.  I noticed a bald patch on the tire and assumed that buying new tires would fix it.  I bought new tires and had the 4 wheel alignment performed.  After that most of the vibration was gone, but not all.  There was a faint constant thudder sound that I can hear even though my wife doesn't notice.  I have noticed the vibration get louder as time went on.  Yesterday I removed the tires to rotate them and see if I could tell where the sound was coming from.  I found the tire was wearing abnormal cupping on every other tread the inside edge of the right rear tire.  I loosened the brake a little and listened to the wheel as I rotated it by hand with out the tire.  I thought I heard a faint ticking in the bearing assembly so I bought a  replacement Wheel Hub assembly.  I switched the cupped worn tire to the left side.  Test drove the car again and I still hear some thudder sound.  It could be the cupped tire now making the sound.  But now I am not sure if the bearing could even have caused the cupping wear in the first place.  What should I be looking for to find the cause for the cupping wear on a rear tire?

Answer
Brad,

Since the cupping is only on one tire, I suspect you have a bad shock.  But it is also possible that the alignment is still bad.

Many folks think that since there is no provision for adjustment on certain suspensions, that you can't adjust them - WRONG!!

There are a lot of ways to adjust suspensions - Eccentric bolts, slotted holes, etc.

So have someone look at both the alignment and the shocks.