Using The Universal Discovery Widget (UDW) with a huge content tree list makes the UWD to stretch below the screen limits, making the selection of bottom elements impracticable.

Steps to reproduce

• Create some elements below Home (around 25 or plus)
• Create a content type with a "content Relation" field, for instance
• Create one object from previous content type.
• When UWD opens, expand the Home folder and try to select the last created element from the list (It's not possible, because there is no scroll-down bar (see image 2)
• click "Cancel Button"
• Not we can see that the part of the UDW that we could not see appears on the top of the screen and don't disapear (see image3).