Add button in editor becomes inaccessible for large collections

This is a general layout problem. The vertical scroll bar in the editor only effects the content area (Body), and does not scroll the TOC area. When you add enough resources (Or if the resources have very long names) the TOC becomes longer the the window (Even at full size) and the add buttons becomes inaccessible. The only way around this is to make more folders and Move assets into them, which may not be desired (And which you can not do because you can not move into an empty folder.)

In the attached screen shot, adding one more asset will make this impossible to add more resources in to the collection (Or at least hard as you would have to add form main site and then edit.)

The TOC area needs its own scroll bar in such cases, or is there are more dynamic way way to use the one scroll bar?

Also please note, the vertical scroll bar is 5 pixels or so away from the edge of the browser window.