I have been wearing RM Williams boots for about 7 years now. The first boots I bought were the Yard boot, swiftly followed by the Blaxland in both brown suede and tan suede. However on purchasing my first pair of Comfort Craftsman I noticed that these boots make a subtle squeaking sound when I walk, like air is escaping from the boot. As such I sold that pair some years ago, but I recently bought another pair and I have noticed that they make the exact same noise; and this is something that I have only experienced with the Comfort Craftsman. Is this normal for these boots or have I just been unlucky?