I have a set of Cobra single length irons and have had 3 shafts break - 5, 6, and 9 iron over a 2 year period. None of the breaks occurred due to hardpan, or chunked hits. I'm 65 years old, have played for 30 years and have had only one club break before this set. Has anyone else had a similar issue. They have all broken right at the top of the hosel.