After changing the date format to dd/mm/YY the advanced search 'Date from' and 'Date to' fields does't work anymore.

Any help very much appreciated.

Check it on my sites here:
http://www.goodwear.nl/index.php?mai...dvanced_search

and here on multilanguage site:
http://81.26.209.93/~itsthat/index.php?main_page=advanced_search

When changing language to English it works so it have to do with the changes in dutch.php inside languages directory.