Andreas Raab uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-kb.180.mcz

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

Name: System-kb.180
Author: kb
Time: 28 November 2009, 12:23:19 pm
UUID: 8164c0e1-ffc4-e34a-b3f0-1cd63d5641dc
Ancestors: System-nice.179

 - fix: implemented missing PragmaPreference >> provider to return its provider ivar. 
 This is needed for Preferences >> removePreferencesFor: to work, as it selects preferences based on their providers, which is implemented in Preference (the superclass of PragmaPreference) as to return nil.

=============== Diff against System-nice.179 ===============

Item was added:
+ ----- Method: PragmaPreference>>provider (in category 'accessing') -----
+ provider
+ 
+ 	^provider!