Hey BK !!!
Her's how Saz explained the Fletchery for me, and it works.
Equip the bow, and one arrow that you want to duplicate. Make sure that the other two quiver slots are open.
Wander around. Check inna while, you'll see the number of arrows growing. You need to move the arrows into your inventory when you hit 50 arrows.
I've got about 200 Dragon Arrows. It is too cool....
------------------
The RudeDawg
Known in these Forgotten Realms as Perin LightEyes
and my girlfriends, Pamila and Pfil