twisting yew Stave/bow when try to string -

[globalmark]

Hi

I posted this in the general Bow section but seen this bit on war bows and not sure were makes more sense -
http://www.primitivearcher.com/smf/index.php/topic,65492.0.html

problem with twisting and flipping yew bow when try to string it.
would be grateful and yew bow builders have a look..