From what you've described, Brad, your scope's fecked.
If as you say, you've gone through it's full range of vertical adjustment and the POI hasn't changed then it's a fault with your scope, your gun may well have not been at it's 'sweet spot' but that doesn't explain the problem as you've described.
As the lads have said though, if it's been laid up unused for quite a while, a new set of seals won't hurt but if the problem's as you've described your main problem's the optics.
Cheers.