Strange – Video is not fluent when options are gone

I have this strange problem:

When I play video it first seems like everything is Ok,
But after few seconds when the video options/info is off (meaning:play button, length bar, headline etc.)then the video start
Stuttering and becomes unfluent. If I point my mouse inside the Kodi window again I plays well again because the options/info are back, and again it will
Go bad when they are off.
It seems like my only option to watch streaming is if I play with the cursor all thetime…
Another strange thing – the problem is only when I’m in full screen.

I’m using windows 7, Pentium dual-core E5300.

Any suggestions?