Okay, the issue with the scrollbar has been solved. I had an HTML5 ad code that apparently broke that. I changed it with a plain image. So that’s okay now.
But what I found is when I ENABLE the W3 Total caching checkbox in the adRotate Misc. settings tab. I get the text echo adrotate_ad(3, true, 0, 0, 0,);.
When I DISABLE (uncheck) this checkbox, it does show the Ad. So it works opposite.
But I don’t know if it will count clicks, etc, because of this.
What does this checkbox do? Apparently the issue IS related to the W3 Total Cache plugin. But what does it look for in W3 Total Cache?