I've experienced a weird problem since the latest Beta got online. The Windows Mouse Pointer sometimes shows at the left hand side in-game. Sometimes it also causes game crashes. I can move around in the game and play as normal, but when movign the screen to the left, the mouse pointer starts appearing. When using "Wait" (T) in-game, the game is sometimes minimized and I'm dropped back to windows.
The 'windows' mouse pointer also showed up a few times if I alt-tabbed. I fixed this by pressing esc in game, opening the system menu, and moving the game mouse pointer. It'll disappear if I do this.