Post-Vars doubled / corrupted

Hello to all, I distributed my app to a new server and suddenly had values saved twice in the db and so on. I tracked it down and found out, that the problem is the content of $_POST. Vars are doubled, Strings corrupted. Absolutely absurd. I have no idea where to search for the reasons. PHP-Version is 4.3.11 Does anybody else have an idea? Thank you in advance Sabine A simple testcase: <?php echo "Post:"; var_dump($_POST); ?> <html> <body >

       <form id="formular" action="<?=$_SERVER['PHP_SELF'] ?>" method="post">
             <ul id="colors">
           <li><input class="buttons" name="colors[]" id="id1" type="checkbox" value="1"  title="chose color" /><label for="id1">red</label></li>
           <li><input class="buttons" name="colors[]" id="id2" type="checkbox" value="2"  title="chose color" /><label for="id2">blue</label></li>
                     <li><input class="buttons" name="colors[]" id="id3" type="checkbox" value="3"  title="chose color" /><label for="id3">green</label></li>
           <li><input class="buttons" name="colors[]" id="id4" type="checkbox" value="4"  title="chose color" /><label for="id4">yellow</label></li>
       </ul>
                                         <fieldset class="nolegend">
               <input type="submit" value="change colors" name="aendern" />&nbsp;&nbsp;&nbsp;
               <input type="submit" value="save colors" name="speichern" />
           </fieldset>          </form>      </body>

</html> Output for $_POST, if you just click on "change colors": Post: array(1) { ["aendern"]=> string(34) "change colorsaendern=change colors" } Output, if you check only "red" and click "change colors": Post: array(2) { ["colors"]=> array(1) { [0]=> string(1) "1" } ["aendern"]=> string(13) "change colors" } output for 2 colors checked: Post: array(2) { ["colors"]=> array(3) { [0]=> string(1) "1" [1]=> string(1) "2" [2]=> string(1) "2" } ["aendern"]=> string(13) "change colors" }