I've noticed an odd phenomenon this summer. Most of my practice is in the back yard at 20-30 yds. The bow is sighted in well--shooting tight enough groups to be hard on my arrows--ie--2 robin hoods, countless fletching hits... etc. Out at 50 and 60 yards, the bow is shooting a foot or more to the right. When I adjusted to center the shots at long range, I'm now shooting 2-3" to the left whenI'm practicing at 20 and 30 yards. I hate to confess my poor form at golf, but the arrow appear to start a little left and then come to the right just like my typical golf shot (my golfing friends tell me its from an outside in swing and that I have too may hobbies). What's up? There are no tuning issues that I can see--the bow groups as well with slick trick 100's as it does feild tips (this is hard on the arrows!). Am I in error to assume that in the absence of wind, an arrow flies straight? Please help--bow season is 10 days away and my confidence is being affected. I'm shooting the following:

2002 Bowtech SC Patriot @ 70#
27" goldtips, 100 grain field points/slick tricks
spot hog real deal sight
quick tune 1000?
I'm shooting with a release and use a peep sight.