diff --git a/app/controllers/cost_reports_controller.rb b/app/controllers/cost_reports_controller.rb
index 833438b2fd..835df710f3 100644
--- a/app/controllers/cost_reports_controller.rb
+++ b/app/controllers/cost_reports_controller.rb
@@ -1,6 +1,7 @@
 class CostReportsController < ApplicationController
   before_filter :find_optional_project, :only => [:index]
   before_filter :generate_query, :only => [:index]
+  before_filter :load_all
 
   helper :reporting
   include ReportingHelper
@@ -117,6 +118,11 @@ class CostReportsController < ApplicationController
     end
   end
 
+  def load_all
+    CostQuery::GroupBy.all
+    CostQuery::Filter.all
+  end
+
   private
   ## FIXME: Remove this once we moved to Redmine 1.0
   def find_optional_project
diff --git a/app/models/cost_query/chainable.rb b/app/models/cost_query/chainable.rb
index 6c8d786150..550a8b0b03 100644
--- a/app/models/cost_query/chainable.rb
+++ b/app/models/cost_query/chainable.rb
@@ -6,8 +6,8 @@ class CostQuery < ActiveRecord::Base
     include CostQuery::QueryUtils
     extend CostQuery::InheritedAttribute
 
-    inherited_attribute   :applies_for,
-                          :default => :label_cost_entry_attributes #this attr. should point to a symbol useable for translations
+    # this attr. should point to a symbol useable for translations
+    inherited_attribute :applies_for, :default => :label_cost_entry_attributes
 
     def self.accepts_property(*list)
       CostQuery.accepted_properties.push(*list.map(&:to_s))
diff --git a/app/models/cost_query/custom_field_mixin.rb b/app/models/cost_query/custom_field_mixin.rb
new file mode 100644
index 0000000000..d84955daa3
--- /dev/null
+++ b/app/models/cost_query/custom_field_mixin.rb
@@ -0,0 +1,57 @@
+module CostQuery::CustomFieldMixin
+  def self.extended(base)
+    base.inherited_attribute :factory
+    base.factory = base
+    super
+  end
+
+  def all
+    @all ||= generate_subclasses
+  end
+
+  def generate_subclasses
+    IssueCustomField.all.map do |field|
+      class_name = class_name_for field.name
+      parent.send(:remove_const, class_name) if CostQuery::GroupBy.const_defined? class_name
+      parent.const_set class_name, Class.new(self).prepare(field, class_name)
+    end
+  end
+
+  def on_prepare(&block)
+    @on_prepare = block if block
+    @on_prepare
+  end
+
+  def prepare(field, class_name)
+    label field.name
+    table_name(class_name.demodulize.underscore.tableize)
+    dont_inherit :group_fields
+    join_table (<<-SQL % [CustomValue.table_name, table_name, field.id, field.name]).gsub(/^    /, "\t")
+    -- BEGIN Custom Field Join: "%4$s"
+    LEFT OUTER JOIN (
+    \tSELECT
+    \t\tvalue AS %2$s,
+    \t\tcustomized_type,
+    \t\tcustom_field_id,
+    \t\tcustomized_id
+    \tFROM
+    \t\t%1$s)
+    AS %2$s
+    ON %2$s.customized_type = 'Issue'
+    AND %2$s.custom_field_id = %3$d
+    AND %2$s.customized_id = entries.issue_id
+    -- END Custom Field Join: "%4$s"
+    SQL
+    instance_eval(&factory.on_prepare)
+    self
+  end
+
+  def new(*)
+    fail "Only subclasses of #{self} should be instanciated." unless self < factory
+    super
+  end
+
+  def class_name_for(field)
+    "CustomField" << field.split(/[ \-_]/).map { |part| part.gsub(/\W/, '').capitalize }.join
+  end
+end
\ No newline at end of file
diff --git a/app/models/cost_query/group_by.rb b/app/models/cost_query/group_by.rb
index 785d619d00..da723a4df5 100644
--- a/app/models/cost_query/group_by.rb
+++ b/app/models/cost_query/group_by.rb
@@ -21,9 +21,6 @@ module CostQuery::GroupBy
     ]
   end
 
-  # trigger eager loading
-  all
-
   def self.all_grouped
     all.group_by { |g| g.applies_for }.to_a.sort { |a,b| a.first.to_s <=> b.first.to_s }
   end
diff --git a/app/models/cost_query/group_by/custom_field.rb b/app/models/cost_query/group_by/custom_field.rb
index c511120c89..620a2ad224 100644
--- a/app/models/cost_query/group_by/custom_field.rb
+++ b/app/models/cost_query/group_by/custom_field.rb
@@ -1,48 +1,6 @@
 module CostQuery::GroupBy
   class CustomField < Base
-    def self.all
-      @all ||= generate_subclasses
-    end
-
-    def self.generate_subclasses
-      IssueCustomField.all.map do |field|
-        class_name = class_name_for field.name
-        CostQuery::GroupBy.send(:remove_const, class_name) if CostQuery::GroupBy.const_defined? class_name
-        CostQuery::GroupBy.const_set class_name, Class.new(self).prepare(field, class_name)
-      end
-    end
-
-    def self.prepare(field, class_name)
-      label field.name
-      table_name(class_name.demodulize.underscore.tableize)
-      dont_inherit :group_fields
-      group_fields table_name
-      join_table(<<-SQL % [CustomValue.table_name, table_name, field.id, field.name])
-      -- BEGIN Custom Field Join: "%4$s"
-      LEFT OUTER JOIN (
-        SELECT
-          value AS %2$s,
-          customized_type,
-          custom_field_id,
-          customized_id
-        FROM
-          %1$s)
-      AS %2$s
-      ON %2$s.customized_type = 'Issue'
-      AND %2$s.custom_field_id = %3$d
-      AND %2$s.customized_id = entries.issue_id
-      -- END Custom Field Join: "%4$s"
-      SQL
-      self
-    end
-
-    def self.new(*)
-      fail "Only subclasses of #{self} should be instanciated." unless self < CustomField
-      super
-    end
-
-    def self.class_name_for(field)
-      "CustomField" << field.split(/[ \-_]/).map { |part| part.gsub(/\W/, '').capitalize }.join
-    end
+    extend CustomFieldMixin
+    on_prepare { group_fields table_name }
   end
 end
diff --git a/app/models/cost_query/inherited_attribute.rb b/app/models/cost_query/inherited_attribute.rb
index 2e4e7a18ad..9fb5f9c34d 100644
--- a/app/models/cost_query/inherited_attribute.rb
+++ b/app/models/cost_query/inherited_attribute.rb
@@ -28,7 +28,7 @@ module CostQuery::InheritedAttribute
     alias singleton_class metaclass unless respond_to? :singleton_class
 
     def define_singleton_method(name, &block)
-      attr_writer name
+      singleton_class.send :attr_writer, name
       singleton_class.class_eval { define_method(name, &block) }
       define_method(name) { instance_variable_get("@#{name}") or singleton_class.send(name) }
     end
diff --git a/app/models/cost_query/sql_statement.rb b/app/models/cost_query/sql_statement.rb
index 43bf7ee3f3..1bcc0cf6b8 100644
--- a/app/models/cost_query/sql_statement.rb
+++ b/app/models/cost_query/sql_statement.rb
@@ -154,7 +154,7 @@ class CostQuery::SqlStatement
       sql = "\n-- BEGIN #{desc}\n" \
       "SELECT\n#{select.map { |e| "\t#{e}" }.join ",\n"}" \
       "\nFROM\n\t#{from.gsub("\n", "\n\t")}" \
-      "\n#{joins.map { |e| "\t#{e}" }.join "\n"}" \
+      "\n\t#{joins.map { |e| e.gsub("\n", "\n\t") }.join "\n\t"}" \
       "\nWHERE #{where.join " AND "}\n"
       sql << "GROUP BY #{group_by.join ', '}\nORDER BY #{group_by.join ', '}\n" if group_by?
       sql << "-- END #{desc}\n"