diff --git a/sources/zweic/Analyzer.scala b/sources/zweic/Analyzer.scala
index 8718328..a4dc9c8 100755
--- a/sources/zweic/Analyzer.scala
+++ b/sources/zweic/Analyzer.scala
@@ -39,7 +39,8 @@
 		  Report.error(tree.pos, "Class already defined: " + name)
 		case None => 
 		  val cs = ClassSymbol(tree.pos, name.name, None);
-		  classScope(name.name) = cs;
+		  classScope = classScope + name.name -> cs;
+		  //classScope(name.name) = cs;
 		  members.foreach(x => analyzeMember(cs,x))
 	  }	  
 	case ClassDef(name, extend, members) =>
@@ -48,7 +49,8 @@
 		  Report.error(tree.pos, "Class already defined: " + name);
 		case None =>
 		  val cs = ClassSymbol(tree.pos, name.name, classScope.get(extend.get.name));
-		  classScope(name.name) = cs;
+		  classScope = classScope + name.name -> cs;
+		  //classScope(name.name) = cs;
 		  members.foreach(x => analyzeMember(cs,x))
 	  }
   }
@@ -68,6 +70,8 @@
 		case MethodDef(name, args, rtype, expr) =>
 			var myVarScope = emptyVarScope;
 
+			myVarScope = myVarScope + "this" -> VarSymbol(ownerClass.pos, "this", IClassType(ownerClass));
+
 			for ( val x <- ownerClass.allFields ) myVarScope = myVarScope + x.name -> x.asInstanceOf[VarSymbol];
 
 			val paramtypes = for ( val f <- args ) yield {
@@ -78,7 +82,6 @@
 			}
 
 			val rt = analyzeType(rtype);
-			checkSubtype(tree.pos, "Return type mismatch", analyzeExpr(myVarScope, expr), rt);
 			name.sym = MethodSymbol(tree.pos, name.name, paramtypes, rt);
 
 			ownerClass.lookupMethod(name.name) match {
@@ -87,6 +90,8 @@
 				case None =>
 				  ownerClass.enterNewMethod(name.sym.asInstanceOf[MethodSymbol]);
 			}
+
+			checkSubtype(tree.pos, "Return type mismatch", analyzeExpr(myVarScope, expr), rt);
   }
 
   // Analyze a statement
@@ -144,7 +149,7 @@
             name.sym = c;
             IClassType(c)
           case None =>
-            Report.error(tree.pos, "Class " + name + " is unknown");
+            Report.error(tree.pos, "type " + name + " is unknown");
             IBadType
         }
     }
@@ -217,12 +222,12 @@
 					Report.error(tree.pos, "Wrong number of arguments for class constructor in " + ct);
 					IBadType
 				}
-				if ( args.map(x => analyzeExpr(varScope, x)).zip(v.allFields.map(y => y.fieldtype))
+				if ( !args.map(x => analyzeExpr(varScope, x)).zip(v.allFields.map(y => y.fieldtype))
 					.forall( x:Pair[Type, Type] => x._1.isSubtype(x._2)) ) {
 					  Report.error(tree.pos, "Incompatible Types: \nrequired:" + v.allFields + 
 								   "\nfound:" + args);						
 					  IBadType;
-					}
+				}
 		  
 				name.sym = v;
 				IClassType(v)