Run this sample code : http://pastebin.com/WDwt3J5M

You will need that image for "folder.png" : http://i.imgur.com/puiPHwG.png

You will see that the second button is not well rendered, like that : http://i.imgur.com/AWSjr5P.png

It should be like that (obtain it by clicking on the second button) : http://i.imgur.com/Zb7thFZ.png

Also note that when you click on a button, everything becomes blurry, is that normal? http://i.imgur.com/14dt2BR.png


FYI, the reason I am using a Group is because the documentation say it :
"ScrollPane layout calculations are based on the layoutBounds rather than the boundsInParent (visual bounds) of the scroll node. If an application wants the scrolling to be based on the visual bounds of the node (for scaled content etc.), they need to wrap the scroll node in a Group. "