Tires: Tire noise on Mazda CX9, Tire Wear

Question
Morning,
I own a 2007 Mazda CX9 Grand Touring model with the 20" rims.  I bought it new in July 07, currently there are 14.5K miles on it. The problem is that when I drive at speeds over 25 miles per hour I hear humming/buzzing noise coming from the front end.  Also the car pulls to the left badly when I rotate the tires per spec-pulling, the issue is corrected if I rotate back to original place.
I took the car to the dealer and they checked out the car and did an alignment and rotated all four tires in an effort to identify the problem. Well the alignment is spot on but the noise is still there. And the pulling to the left occurred so they re-rotated the tires and told me that Mazda has issued a tech bulletin and that is the current fix for this problem,  The noise did not shift and still comes from the front end.  I also notice that when I turn the car to the right the noise gets louder and when I turn to the left the noise gets softer/decreases.  I took the car to a Bridgestone dealer and after examining the tires he explained to me that the tires have a chop and flat spots in them that's being caused by something in the front end suspension system.  And the dealer needs to fix it under warranty and pro-rate new tires as the current tires should last 30-40K before needing replacement.  

I'm also thinking I could have a bad set of tires from the get-go.

Any guidance you can offer would be helpful to me.

Thanks, Dave

Answer
Dave,

It sounds like you had a problem and it was corrected - the alignment - except that the result - irregular wear on the tires - hasn't been fixed.  That will either take more time to wear a new pattern into the tires - or new tires.

BUT

It also sounds like you have a problem unrelated to the tires - the noise.  Since moving the tires did not affect it, it has to be something other than tires and rims.

But I think you will have problems getting Mazda to handle this under warranty as tire wear is not covered by waranty - and neither is alignment.

My advice would be to go back to Mazda and see what they will do - and hope for the best.