Marcel Taeumel uploaded a new version of Morphic to project The Trunk:
http://source.squeak.org/trunk/Morphic-mt.904.mcz

==================== Summary ====================

Name: Morphic-mt.904
Author: mt
Time: 19 April 2015, 1:16:39.184 pm
UUID: 2a34fcc3-9587-8641-a735-f760c1d695ed
Ancestors: Morphic-mt.903

The customized layout mechanism of scroll panes makes it necessary to compute the fullbounds before layouting proportionally...

=============== Diff against Morphic-mt.903 ===============

Item was changed:
  ----- Method: ScrollPane>>layoutProportionallyIn: (in category 'layout') -----
  layoutProportionallyIn: newBounds
  	"We need to trigger our customized layout mechanism before layouting proportionally."
  
  	self layoutFrame ifNil:[^self].
  	
+ 	self fullBounds.
- 	fullBounds ifNil: [
- 		self
- 			resizeScrollBars;
- 			resizeScroller;
- 			hideOrShowScrollBars].
  
  	^ super layoutProportionallyIn: newBounds.!