I installed a new system from scratch using the Beta 2 64 bit disk. I ran into the same problem detailed above. However, I removed the drivers (2 of them) then re-installed using the Preferences->Appearance->Visual Effects and selecting normal. This initiated the search for drivers. I followed through that process, rebooted, and now all is working.
I installed a new system from scratch using the Beta 2 64 bit disk. I ran into the same problem detailed above. However, I removed the drivers (2 of them) then re-installed using the Preferences- >Appearance- >Visual Effects and selecting normal. This initiated the search for drivers. I followed through that process, rebooted, and now all is working.