After exporting to video there is blurry dotted line on movie display.
Did you use the screen-recorder? I believe the screen-recorder included in NX is not the best way to capture high quality videos. Personally, I never use it.
I would either :
1. Use export => Mechanism => mpeg2(or anything else),
2. Record using Camtasia from Techsmith.
There is a way of making high-quality rendered videos using option 1, but the dialogue box for this option is pretty hard to understand. Let me know if you need any assistance with this. Making still camera animations or turntables are not that hard.