diff --git a/Makefile b/Makefile
index 2d1d5df..0563c08 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 CC=g++
-CFLAGS=-c -g -Wall -rdynamic
+CFLAGS=-c -g -Wall -rdynamic -D_DEBUG
 LDFLAGS=-g -rdynamic
 
 SOURCES=  \
diff --git a/TinyJS.cpp b/TinyJS.cpp
index c1aa3fc..4a10f46 100755
--- a/TinyJS.cpp
+++ b/TinyJS.cpp
@@ -97,6 +97,7 @@
    Version 0.30 :  Rlyeh Mario's patch for Math Functions on VC++
    Version 0.31 :  Add exec() to TinyJS functions
                    Now print quoted JSON that can be read by PHP/Python parsers
+                   Fixed postfix increment operator
 
     NOTE:
           Constructing an array with an initial length 'Array(5)' doesn't work
@@ -1751,8 +1752,11 @@ CScriptVarLink *CTinyJS::expression(bool &execute) {
             if (execute) {
                 CScriptVar one(1);
                 CScriptVar *res = a->var->mathsOp(&one, op==LEX_PLUSPLUS ? '+' : '-');
+                CScriptVarLink *oldValue = new CScriptVarLink(a->var);
                 // in-place add/subtract
                 a->replaceWith(res);
+                CLEAN(a);
+                a = oldValue;
             }
         } else {
             CScriptVarLink *b = term(execute);
diff --git a/run_tests.cpp b/run_tests.cpp
index de04fcd..4e39803 100644
--- a/run_tests.cpp
+++ b/run_tests.cpp
@@ -36,6 +36,9 @@
 #include <sstream>
 #include <stdio.h>
 
+#ifdef MTRACE
+  #include <mcheck.h>
+#endif
 
 //#define INSANE_MEMORY_DEBUG
 
@@ -238,6 +241,9 @@ bool run_test(const char *filename) {
 
 int main(int argc, char **argv)
 {
+#ifdef MTRACE
+  mtrace();
+#endif
 #ifdef INSANE_MEMORY_DEBUG
     memtracing_init();
 #endif
@@ -271,10 +277,15 @@ int main(int argc, char **argv)
 #ifdef INSANE_MEMORY_DEBUG
     memtracing_kill();
 #endif
-#ifdef _WIN32
+
 #ifdef _DEBUG
+ #ifdef _WIN32
   _CrtDumpMemoryLeaks();
+ #endif
 #endif
+#ifdef MTRACE
+  muntrace();
 #endif
+
   return 0;
 }
diff --git a/tests/test008.js b/tests/test008.js
index 8596ee2..b0d5525 100644
--- a/tests/test008.js
+++ b/tests/test008.js
@@ -1,5 +1,5 @@
 // functions in variables
-var bob;
+var bob = {};
 bob.add = function(x,y) { return x+y; };
 
 result = bob.add(3,6)==9;
diff --git a/tests/test014.js b/tests/test014.js
index 9c2bb30..5538c54 100644
--- a/tests/test014.js
+++ b/tests/test014.js
@@ -1,6 +1,7 @@
 // Variable creation and scope from http://en.wikipedia.org/wiki/JavaScript_syntax
 x = 0; // A global variable
 var y = 'Hello!'; // Another global variable
+z = 0; // yet another global variable
 
 function f(){
   var z = 'foxes'; // A local variable
diff --git a/tests/test017.js b/tests/test017.js
index 0f6be1b..ebebe01 100644
--- a/tests/test017.js
+++ b/tests/test017.js
@@ -1,6 +1,6 @@
 // references for arrays
 
-var a;
+var a = [];
 a[0] = 10;
 a[1] = 22;
 
diff --git a/tests/test018.js b/tests/test018.js
index 52da3d1..1432de0 100644
--- a/tests/test018.js
+++ b/tests/test018.js
@@ -1,7 +1,7 @@
 // references with functions
 
 var a = 42;
-var b;
+var b = [];
 b[0] = 43;
 
 function foo(myarray) {
diff --git a/tests/test023.js b/tests/test023.js
index 619c486..b40d427 100644
--- a/tests/test023.js
+++ b/tests/test023.js
@@ -1,4 +1,5 @@
 // mikael.kindborg@mobilesorcery.com - Function symbol is evaluated in bracket-less body of false if-statement
+var foo; // a var is only created automated by assignment
 
 if (foo !== undefined) foo();