Never mind, Jason
I got it working
I changed
if ((WA_eCart_FormatNumber($screenroom->DisplayInfo("Price") - (($screenroom->DisplayInfo("Price")/$screenroom->TotalColumn("TotalPrice")) * $screenroom->GetDiscounts()), false, 2) > 0)) {
?>
<input type="hidden" name="amount_<?php echo $screenroom_Index+1; ?>" id="amount_<?php echo $screenroom_Index+1; ?>" value="<?php echo WA_eCart_FormatNumber($screenroom->DisplayInfo("Price") - (($screenroom->DisplayInfo("Price")/$screenroom->TotalColumn("TotalPrice")) * $screenroom->GetDiscounts()), false, 2) ?>" />
to
if ((WA_eCart_FormatNumber($screenroom->DisplayInfo("Price") - (($screenroom->DisplayInfo("Price")/$screenroom->TotalColumn("TotalPrice")) * $screenroom->GetDiscounts()), false, 2) > 0)) {
?>
<input type="hidden" name="amount_<?php echo $screenroom_Index+1; ?>" id="amount_<?php echo $screenroom_Index+1; ?>" value="<?php echo WA_eCart_FormatNumber($screenroom->DisplayInfo("truePrice") - (($screenroom->DisplayInfo("Price")/$screenroom->TotalColumn("TotalPrice")) * $screenroom->GetDiscounts()), false, 2) ?>" />
thanks for your help, as always