Ok, heres the deal: I recieved a Bark river psk on monday, and I noticed the sheath retention was not that great. I used a hairdryer to reform the mouth of the sheath to lock in tighter and farther in. It now holds it to the first handle pin. It holds it with proper tension now, but the every time I leave it sitting on a table, or wear it, an hour later when I try to dry it out, It becomes really tight on its own, and I just have to yank the knife, trying not to break my neck. Then when I put it in the exact same way, it is the perfect retension, but then again, next time I reach for it, it has become tight. Any idea what is going on?