Shooting a 68" longbow with a fairly straight type handle and noticed the bow twists in my hand after release.

I shoot right handed and the bow ends up with the string to the left, maybe 1 or 2" off centre.

Is my grip wrong, my handle wrong or is it a form / release thing?

Thanks in advance for your input.

Loose grip and let it do it's thing..at least that's how I look at it..could be wrong so let's hear what others have to say.

This may help also assuming the straight grips are the same..
http://www.howardhillshooters.com/hillgrip/hillgrip.html  
Regards,
 Dave