Problems with tools

Hy, I am new here. I am using sketchup just for fun. I have a problem with the tools after one click they leaf something like a track??? It makes me crazy… I didn’t found something in all the forums. I am shure its just one click to solve it. Here is a picture.

I am not sure if that is allowed…

It looks like a graphic related issue.
Try this : Window->Preferences->OpenGL-> untick ‘use fast feedback’