i think for both problems, you should use:
<?php echo ($row_rsTeacups['DetailPage']); ?>-<?php echo $row_rsTeacups['ProdId']; ?>.html
as the form action for the add to cart foprm and the add to waiting list form:
action="<?php echo ($row_rsTeacups['DetailPage']); ?>-<?php echo $row_rsTeacups['ProdId']; ?>.html">
also, rearange the code so that the validation comes after the rsTeacups recordset, and edit the validation failed redirect:
$WAFV_Redirect = "".(htmlentities($_SERVER["PHP_SELF"], ENT_QUOTES)) ."?invalid=true";
to use the same recordset reference:
$WAFV_Redirect = "".$row_rsTeacups['DetailPage']."-".$row_rsTeacups['ProdId']."?invalid=true";