About 2 weeks ago I was hitting with my Head Microgel Radical OS tennis racquet. After about 40 minutes of hitting, I immediately felt something was off about my racquet. I thought it was my strings because I was getting a "boing" noise rather than a "pop". It also was hitting longer and the tension felt as though it dropped all of a sudden. It also felt like the ball was going further into my string bed. I went to string my tennis racquet at DHL Tennis and hoped that it would fix the problem. It didn't. I bought this racquet at Tennis Warehouse on December 2010 strung with Prince Synthetic Gut 16g at 58 tension. I strung with the same string and the same tension at DHL Tennis. I do use a Vibration Dampener for my racket (tried 2 different kinds and still got that "boing/springy" noise). I'm really disappointed because the last thing I want is my money down the drain . If anyone can provide any information or tell me any information they want me to add, please say so. Greatly appreciated.