Spot on, Patch, SPOT ON!!!
It's likely grip if you don't normally do this. If you are "choking" the bow, you pull your forearm into the "line of fire" almost automatically. If I use a "high wrist grip," I can shoot a 31" bow, but I'm only a true 29" draw based on my wingspan. Check out this link:
http://www.bowsite.com/bowsite/featu...grip/index.htm It has some good info on grip. But you also need to make sure your form is CONSISTENT. I shoot a few arrows at least 5 days a week. It might only be 4-5 some days, but I get a few arrow flying out of my bows to make sure I'm keeping the "muscle memory" and form consistent.