I'm fairly certain this is an intel igpu driver issue. I have an asus p8z77-v deluxe and 3770k, and I've spent hours messing with my new 8.1 install... with the 10.18.10.3262 igpu drivers QuickSync encoding works fine. However, with the recommended 9.17.10.3223 driver (why it is reccomended even with a lower driver number I have no idea), OBS crashes and there is also a second cursor in the top left of my main display. I would suggest trying to get the latest driver version for your motherboard.
There is also a higher 10.18.10.3316 driver version on the intel website that I haven't tried yet, but things are working for me now so I won't be messing with it until i have some more spare time.