Having Trouble Dropping an Object Into a Scrolling Panel

I have a presentation with a few scrolling panels, and up until about a week ago, I had no problems adding new objects into my scrolling panels. Lately, however, I can't get anything to stick in the panel. I am trying to add a new image to the panel by dragging the object with my cursor over the panel and letting go. When I then try to scroll, the object is just in front of the panel not in it.

Help?