Just noticed an issue in this latest build. When you hover over a running app preview in the taskbar for media programs such as winamp, wmp, groove, vlc, you are unable to hit the back, pause/play, or forward buttons in the preview. The preview immediately closes. So, you are forced to open the app up entirely to make those selections. Did not have this issue in the last build.
You need to move your cursor into the thumbnail for the 'reveal hover' when the thumbnail takes on the accent color, (pic 2),
as opposed to a preview hover from the taskbar, (pic 1), then you'll be able to utilize the controls.

