seekbar problems

Hellou, 

please, have anybody of you some experience with this???

I enter a pictures of it. 

I want to have a seekbar for only slected slides, so I set that in Slide seetings, fot only slected slide . I havent got seekbar on other slide, but there is a grey square instead of that. And I dont want it there, becouse the size of full sreen is than smaller. I hope you understand me and you know help me. 

thanks a lot