I was playing yesterday with one of my new Prestige MPs and it made a weird buzzing sound whenever I hit full shot but not when I hit a slice. I was concerned it was a flaw in the frame but I had a rubber band in my bag so I tied it around the two main strings and the buzz was completely eliminated. It wasn't the usual pinging sound without a dampener that the other two racquets make but something different. Any idea what it could be since it was quieted by a rubber band around the two mains? I'm assuming the frame is fine but I'm still curious about it. Thanks in advance.