It seems this problem has been there for a while. I have this problem in ADE 2.0 and 3.0. I solve this problem on my computer today.
This problem is not a "turnning page" problem but an UI refresh problem, if you turn page, close ADE and reopen it, you will find the page actually turnned, I guess this problem occurs on a computer which have two display card. On my laptop, a NVIDIA, and an integrated. ADE works fine on NVIDIA and not on the integrated one.
So Here is my solution: Tell ADE not running on the integrated display card but on NVIDIA. You can do so by using NVIDIA's control panel program. "manage 3D settings" -> "program setting" tab, add ADE, and tell it running on NVIDIA.