diff --git a/db.class.php b/db.class.php
index c844e19..51ad829 100644
--- a/db.class.php
+++ b/db.class.php
@@ -472,7 +472,7 @@ class MeekroDB {
       
       if ($arg_number_length = strspn($sql, '0123456789', $new_pos_back)) {
         $arg_number = substr($sql, $new_pos_back, $arg_number_length);
-        if (! isset($args_all[$arg_number])) $this->nonSQLError("Non existent argument reference (arg $arg_number): $sql");
+        if (! array_key_exists($arg_number, $args_all)) $this->nonSQLError("Non existent argument reference (arg $arg_number): $sql");
         
         $arg = $args_all[$arg_number];
         
@@ -481,8 +481,8 @@ class MeekroDB {
           $new_pos_back + $named_seperator_length) + $named_seperator_length;
         
         $arg_number = substr($sql, $new_pos_back + $named_seperator_length, $arg_number_length - $named_seperator_length);
-        if (count($args_all) != 1) $this->nonSQLError("If you use named parameters, the second argument must be an array of parameters");
-        if (! isset($args_all[0][$arg_number])) $this->nonSQLError("Non existent argument reference (arg $arg_number): $sql");
+        if (count($args_all) != 1 || !is_array($args_all[0])) $this->nonSQLError("If you use named parameters, the second argument must be an array of parameters");
+        if (! array_key_exists($arg_number, $args_all[0])) $this->nonSQLError("Non existent argument reference (arg $arg_number): $sql");
         
         $arg = $args_all[0][$arg_number];
         
diff --git a/simpletest/BasicTest.php b/simpletest/BasicTest.php
index 23c8294..5be8df1 100644
--- a/simpletest/BasicTest.php
+++ b/simpletest/BasicTest.php
@@ -65,12 +65,21 @@ class BasicTest extends SimpleTest {
       'height' => 155.23,
       'favorite_word' => null,
     ));
-    
+
     $this->assert(DB::insertId() === 3);
-    
     $counter = DB::queryFirstField("SELECT COUNT(*) FROM accounts");
     $this->assert($counter === strval(3));
-    
+
+    DB::insert('`accounts`', array(
+      'username' => 'Deer',
+      'password' => '',
+      'age' => 15,
+      'height' => 10.371
+    ));
+
+    $username = DB::queryFirstField("SELECT username FROM accounts WHERE password=%s0", null);
+    $this->assert($username === 'Deer');
+
     $password = DB::queryFirstField("SELECT password FROM accounts WHERE favorite_word IS NULL");
     $this->assert($password === 'goodbye');
     
@@ -111,7 +120,7 @@ class BasicTest extends SimpleTest {
     $this->assert($results[0]['age'] == 30 && $results[0]['password'] == 'goodbye');
     
     $results = DB::query("SELECT * FROM accounts WHERE username!=%s", "Charlie's Friend");
-    $this->assert(count($results) === 2);
+    $this->assert(count($results) === 3);
     
     $columnlist = DB::columnList('accounts');
     $this->assert(count($columnlist) === 6);