Mine did that for a while then settled in and now is very steady. But from my experience with the Edgestar 28, 4 ChasDen All Cedar Drawers and 2 Cedar Shelves 1.5 # of beads is not enough. I started with that and ended up at 2.5# before it behaved like I wanted. I have mine set at the highest temp and it holds right at 66 degrees, I do not turn it off and on.
Another lesson learned was do not make changes too quickly - it takes several weeks for things to settle down after any kind of adjustments to the setup.