Frank Shearar uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-fbs.513.mcz

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

Name: Collections-fbs.513
Author: fbs
Time: 26 April 2013, 11:13:00.656 am
UUID: dba4f808-6844-414c-a5bf-5cda0cf4e342
Ancestors: Collections-bf.512

This fixes the recent report of an Ubuntu 13.04 machine not being able to save a class comment.

https://bugzilla.redhat.com/show_bug.cgi?id=956376

=============== Diff against Collections-bf.512 ===============

Item was changed:
  ----- Method: WriteStream>>nextChunkPut: (in category 'fileIn/Out') -----
  nextChunkPut: aString
  	"Append the argument, aString, to the receiver, doubling embedded terminators."
  
  	| i remainder terminator |
  	terminator := $!!.
  	remainder := aString.
  	[(i := remainder indexOf: terminator) = 0] whileFalse:
  		[self nextPutAll: (remainder copyFrom: 1 to: i).
  		self nextPut: terminator.  "double imbedded terminators"
  		remainder := remainder copyFrom: i+1 to: remainder size].
  	self nextPutAll: remainder.
  	aString includesUnifiedCharacter ifTrue: [
  		self nextPut: terminator.
  		self nextPutAll: ']lang['.
  		aString writeLeadingCharRunsOn: self.
  	].
  	self nextPut: terminator.
+ 	self flush.
  !