when i try your link, i see the following error:
Warning: implode() [function.implode]: Invalid arguments passed in /home/jdekeyre/public_html/keywesthistoricmarkertour.org/PostCards_Results.php on line 84
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')) GROUP BY GroupingID ORDER BY ProductPrice LIMIT 0, 10' at line 1
send me a copy of the PostCards_Results.php page in a zip archive so i can look at the code.