Screen is not properly refreshed & OpenGL does not properly work in OpenCV

Hi all

I am using the Nvidia Jetson TK1, to do some stuffs about Computer Vision. And I have 2 problems: 1. The screen is not properly refreshed (even when I am only using internet or reading a PDF), so I need to know if this is normal or if it has some bug or something or how can I fixed it. 2. If I use OpenGL with OpenCV, the algorithms (in C++) are even slower.

Thank you so much for you help in advance!!!