diff --git a/app/models/dmsf_file.rb b/app/models/dmsf_file.rb
index 2b4c7eba..924f2fea 100644
--- a/app/models/dmsf_file.rb
+++ b/app/models/dmsf_file.rb
@@ -44,8 +44,8 @@ class DmsfFile < ActiveRecord::Base
   has_many :referenced_links, :class_name => 'DmsfLink', :foreign_key => 'target_id', 
     :conditions => {:target_type => DmsfFile.model_name}, :dependent => :destroy
   
-  scope :visible, where('NOT deleted')
-  scope :deleted, where('NOT NOT deleted')
+  scope :visible, where(:deleted => false)
+  scope :deleted, where(:deleted => true)
   
   validates :name, :presence => true
   validates_format_of :name, :with => DmsfFolder.invalid_characters,
diff --git a/app/models/dmsf_file_revision.rb b/app/models/dmsf_file_revision.rb
index 70bdefb3..ec252390 100644
--- a/app/models/dmsf_file_revision.rb
+++ b/app/models/dmsf_file_revision.rb
@@ -29,8 +29,8 @@ class DmsfFileRevision < ActiveRecord::Base
   has_many :dmsf_workflow_step_assignment, :dependent => :destroy
 
   # Returns a list of revisions that are not deleted here, or deleted at parent level either  
-  scope :visible, where('NOT deleted')
-  scope :deleted, where('NOT NOT deleted')
+  scope :visible, where(:deleted => false)
+  scope :deleted, where(:deleted => true)
 
   acts_as_customizable
   acts_as_event :title => Proc.new {|o| "#{l(:label_dmsf_updated)}: #{o.file.dmsf_path_str}"},
diff --git a/app/models/dmsf_folder.rb b/app/models/dmsf_folder.rb
index 81e3b124..7662fc59 100644
--- a/app/models/dmsf_folder.rb
+++ b/app/models/dmsf_folder.rb
@@ -45,8 +45,8 @@ class DmsfFolder < ActiveRecord::Base
     :conditions => {:entity_type => 1},
     :dependent => :destroy
   
-  scope :visible, where('NOT deleted')
-  scope :deleted, where('NOT NOT deleted')
+  scope :visible, where(:deleted => false)
+  scope :deleted, where(:deleted => true)
 
   acts_as_customizable
     
diff --git a/app/models/dmsf_link.rb b/app/models/dmsf_link.rb
index ba84544e..39820776 100644
--- a/app/models/dmsf_link.rb
+++ b/app/models/dmsf_link.rb
@@ -27,8 +27,8 @@ class DmsfLink < ActiveRecord::Base
   validates :target_id, :presence => true
   validates_length_of :name, :maximum => 255    
   
-  scope :visible, where('NOT deleted')
-  scope :deleted, where('NOT NOT deleted')
+  scope :visible, where(:deleted => false)
+  scope :deleted, where(:deleted => true)
   
   def target_folder_id
     if self.target_type == DmsfFolder.model_name