Updates: Status: Fixed
Comment #8 on issue 799 by chisvasi...@gmail.com: Editing code in Glamour must be faster http://code.google.com/p/moose-technology/issues/detail?id=799
The problem was that PluggableTextMorph was created with autoAccept: true. This means that GLMMorphicModel>>accept:notifying: is called on each key stroke which completely replaces the text, recompiles it and redoes the highlighting twice.