Identical description for me as well... that's what betas are all about, they say. Let's hope we have a fix sooner than to expect another beta release, maybe a patch file, a workaround or even a new version of the same beta.

As a workaround, I installed Beta 6 (complete pkg) over beta 8 to restore my display use. I guess the solution will be in the next beta (9).

Beta 9, released today (Wednesday, October 6th), apparently resolved all this issue. I just installed it over Beta 6 and everything went ok.