I read your post 2 times and im still not sure what your saying.If everything is shooting fine out to 30 yards then i dont get it.
Couple of other things i can think of is line your pin groups up with your string,almost center shot from your arrow rest.
Are you using a peep site?Maybe your draw length is a little long and you are canting your head to look through the peep.
Hopefully someone with alot more knowledge will step forward and set the record straight
And welcome aboard russelllaw.Great place to be and ask alot of questions and answer a few as well