Kelly,
When I did hang my shafts, I did hang them small end up. I was told by cuemakers the reasoning for both ways. My choice was to put them small end up, because that is where I wanted to insert my cup hook. Also I have noticed that if you store the shafts close to a wall, those shafts will more likely go out, and the ones towards the middle stay straight

Sounds silly, but I believe it is because the temperature change here in Indiana. 70 one day, and 10 the next

. I now keep them all in the center of my shop, and it yeilds more shafts

I have never noticed one end or the other moving on me, I will try to notice that. It makes sense to me though, because your flooring will draw moisture as the wall will. Is your holder right on the floor, or is there clearance? Mine is about 6 inches off the floor, just curious. Very interesting though... My wood does not talk each other though, I have been to the shop late at night, and I do not hear anything
Jim