I upgraded to the Thunderbolt on 4/1. Exchanged it for a droid 2 (for smaller size and keyboard) on 4/10. Quickly realized my mistake and had to buy it again at upgrade price on 4/11. Now to my point... While setting up the phone I realized a very big difference in the haptic feedback and vibration on the 2nd Thunderbolt. It is very weak and makes a buzzing noise when keys are pressed, giving it a cheap or refurbished feel. I know the TB I had a day earlier had a deeper vibration which gave the phone a solid feel. Was wondering why such a diference on such a new phone? And if there's a way to fix it or send it somewhere to be fixed?