Not sure if I'm providing any new information here, but I encountered this as well. The issue was of course the change to scroll frames, as they will not clip their children automatically unless defined either in XML or lua. To solve this, I simply put this in my scroll frame wrapper:
Lua Code:
frame:SetClipsChildren(true)
In XML, the tag is
clipChildren="true". This causes any children outside the boundaries of the frame to be unclickable and frankly not drawn at all. Any scroll frame now also returns an object type of plain "Frame", suggesting that the specific "ScrollFrame" widget doesn't exist anymore and is now an intrinsic frame template that simply provides scrolling and child anchoring methods.