I think the following patch will fix the problem.
diff --git a/app/models/time_entry_query.rb b/app/models/time_entry_query.rb
index c8f8eeaeb..c5c2099ad 100644
--- a/app/models/time_entry_query.rb
+++ b/app/models/time_entry_query.rb
@@ -25,7 +25,7 @@ class TimeEntryQuery < Query
QueryColumn.new(:project, :sortable => "#{Project.table_name}.name", :groupable => true),
QueryColumn.new(:spent_on, :sortable => ["#{TimeEntry.table_name}.spent_on", "#{TimeEntry.table_name}.created_on"], :default_order => 'desc', :groupable => true),
TimestampQueryColumn.new(:created_on, :sortable => "#{TimeEntry.table_name}.created_on", :default_order => 'desc', :groupable => true),
- QueryColumn.new(:tweek, :sortable => ["#{TimeEntry.table_name}.spent_on", "#{TimeEntry.table_name}.created_on"], :caption => :label_week),
+ QueryColumn.new(:tweek, :sortable => ["#{TimeEntry.table_name}.tyear", "#{TimeEntry.table_name}.tweek"], :caption => :label_week),
QueryColumn.new(:author, :sortable => lambda {User.fields_for_order_statement}),
QueryColumn.new(:user, :sortable => lambda {User.fields_for_order_statement}, :groupable => true),
QueryColumn.new(:activity, :sortable => "#{TimeEntryActivity.table_name}.position", :groupable => true),