rock hunter,
If you're shooting split finger it might be your bow's sight window. The longbow more than likely has a very short sight window and the recurve's is likely an inch or two or more longer. The short sight window on the longbow might be blocking your dominate eye from seeing your point of aim at closer shots. This could be the case no matter how you aim whether instinctively, gap or other method. When you cant the bow it moves the riser out of the way so you can actually see the spot with both eyes. At least this is my experience. I shoot split finger and my point on is 60 yards so at 20 yards the arrow is pointed a couple feet below the target. With this low of a hold the sight window on my longbows actually blocks the spot I'm trying to hit and I only notice if I close one eye. I know I shoot much better with the bow canted slightly when shooting close.
Try this - Come to full draw, get your sight picture, don't release the arrow, now close your left eye (assuming you're right handed) and see if you can see the spot. If you see the riser above the sight window instead of the spot you've discovered the problem.
If this doesn't help my friend Greg's post above might have more meaning to you.