ORIGINAL: gibblet
when you bottomed it out you made your ata longer. if you weren't perfect where you were, the nock height could have changed because 1 limb could have taken more turns - getting longer than the other one. also it could change your center shot a bit. the slight change in ata effects the angle the cables take to the slide, which can affect rights and lefts - so i'd walk back tune it again - as its your only option - before playing w/ spine if you think that's right.
What he said. I was going to respond to this but he managed to sum up what I was going to say with fewer words than I would have used. This is one of the disadvantages of a cable guard.
Stick a piece of tape vertically on your target butt. Check with a level or plumb bob to make sure it is perfectly level and attach a spot to the top of the line to aim at. Shoot one at it from 10 yards aiming at the spot. Adjust the sight so you are hitting it from 10 yards. Then step back to 20, 25, 30, 35, 40 yards aiming at the same spot. If your pattern drops vertically, you are fine. If your pattern starts to gradually shift left/right you have a center shot problem that was caused by what gibblet mentioned. If the pattern starts to drop, then move left/right and then comes back into center, and then possibly back out to left right as you walk back then you have a spine problem. Don't count your bad shots.......you should know if they are good shots or not.
How long is that shaft exactly from throat of nock to end of carbon? How much weight in the front of it? What is your draw length?