My friend gave me his racquet to string, but after I took out the strings and checked the frame, I found a very small hairline crack going across the width of the frame, along a grommet. I'm afraid to string this because of the crack. Has anyone ever seen a k90 tour cracked at the throat right at the first grommet from the center?? It's right above the 'l' in Wilson and the 'i' on the other side of the racquet. Could it have cracked due to dropping the racquet b/c my friend has dropped it several times but I would have expected the crack to occur at the head or elsewhere. Or could it have happened at some other time during the previous stringings???