Index: /activerdf-1.6.10/lib/active_rdf/federation/federation_manager.rb
===================================================================
--- /activerdf-1.6.10/lib/active_rdf/federation/federation_manager.rb	(revision 146)
+++ /activerdf-1.6.10/lib/active_rdf/federation/federation_manager.rb	(revision 151)
@@ -30,5 +30,5 @@
   # and aggregating the results
   def FederationManager.query(q, options={:flatten => true})
-    
+   
 		if ConnectionPool.read_adapters.empty?
 			raise ActiveRdfError, "cannot execute query without data sources" 
@@ -38,6 +38,5 @@
     # and yield them consequtively
     if block_given?
-      ConnectionPool.read_adapters.each do |source|
-        
+      ConnectionPool.read_adapters.each do |source|        
         source.query(q) do |*clauses|
           yield(*clauses)
@@ -50,12 +49,11 @@
       # were filtered out when doing results.union)
       results = []
-      ConnectionPool.read_adapters.each do |source|
-         
+      ConnectionPool.read_adapters.each do |source|         
 				source_results = source.query(q)
 				source_results.each do |clauses|
 					results << clauses
-				end
 			end
-
+			end
+ 
       # filter the empty results
       results.reject {|ary| ary.empty? }
@@ -70,5 +68,5 @@
       # to prevent unnecessarily nested array [[eyal],[renaud],...]
       results.flatten! if q.select_clauses.size == 1 or q.ask?
-
+    
       # remove array (return single value or nil) if asked to
       if options[:flatten] or q.count?
Index: /activerdf-1.6.10/lib/active_rdf/objectmanager/object_manager.rb
===================================================================
--- /activerdf-1.6.10/lib/active_rdf/objectmanager/object_manager.rb	(revision 25)
+++ /activerdf-1.6.10/lib/active_rdf/objectmanager/object_manager.rb	(revision 151)
@@ -67,4 +67,5 @@
 
 		# look whether class defined in that module
+    begin 
 		if _module.const_defined?(klassname.to_sym)
       $activerdflog.debug "ObjectManager: construct_class: given class #{klassname} defined in the module"
@@ -78,5 +79,8 @@
 			klass.class_uri = resource
 			klass
-		end
+	end
+  rescue
+    puts "ActiveRDF could not create class with this name: #{klassname}"
+    end 
 	end
 
Index: /activerdf-1.6.10/lib/active_rdf/objectmanager/resource.rb
===================================================================
--- /activerdf-1.6.10/lib/active_rdf/objectmanager/resource.rb	(revision 146)
+++ /activerdf-1.6.10/lib/active_rdf/objectmanager/resource.rb	(revision 151)
@@ -29,14 +29,14 @@
     $triple
     # creates new resource representing an RDF resource
-    def initialize uri
+    def initialize uri      
       @uri = case uri
         # allow Resource.new(other_resource)
-        when RDFS::Resource || BNode
+      when RDFS::Resource || BNode               
         uri.uri
         # allow Resource.new('<uri>') by stripping out <>
-        when /^<([^>]*)>$/
+      when /^<([^>]*)>$/      
         $1
         # allow Resource.new('uri')
-        when String
+      when String           
         uri
       else 
@@ -385,5 +385,5 @@
 		# self.class, which does not do a database query, but simply returns 
 		# RDFS::Resource.
-		def type
+		def type   
 			types.collect do |type|
 				ObjectManager.construct_class(type)
@@ -405,11 +405,10 @@
 
 		# overrides built-in instance_of? to use rdf:type definitions
-		def instance_of?(klass)    
-    
-    if klass.to_s == BNode.to_s || self.class.to_s == BNode.to_s
+		def instance_of?(klass)        
+    if klass.to_s == BNode.to_s || self.class.to_s == BNode.to_s     
+      return (klass.to_s == self.class.to_s) ? true : false
+    else  
      
-      return (klass.to_s == self.class.to_s) ? true : false
-    else
-      self.type.include?(klass)
+     self.type.include?(klass)
     end
     end
@@ -517,7 +516,6 @@
 		# returns all rdf:types of this resource but without a conversion to 
 		# Ruby classes (it returns an array of RDFS::Resources)
-		def types
+		def types    
 			type = Namespace.lookup(:rdf, :type)
-
 			# we lookup the type in the database
 			#types = Query.new.distinct(:t).where(self,type,:t).execute
@@ -528,5 +526,5 @@
 			defaults << Namespace.lookup(:rdfs,:Resource)
 			defaults << self.class.class_uri
-
+     
 			(types + defaults).uniq
 		end