Thank you! I just came across this same problem of products with 'Show Products Quantity Box' set to OFF not allowing the Qty box to be editable in the shopping cart.

This custom code did the trick. It works great with the product Attribute Grid mod now, since that mod uses it's own quantity boxes.

Quote Originally Posted by johnswan View Post
The solution was found by commenting out some lines in templates/YOUR_TEMPLATE/templates/tpl_shopping_cart_default.php

At around line 67 you will find the following:
Code:
<?php
  if ($product['flagShowFixedQuantity']) {
    echo $product['showFixedQuantityAmount'] . '<br /><span class="alert bold">' . $product['flagStockCheck'] . '</span><br /><br />' . $product['showMinUnits'];
  } else {
    echo $product['quantityField'] . '<br /><span class="alert bold">' . $product['flagStockCheck'] . '</span><br /><br />' . $product['showMinUnits'];
  }
?>
Delete or comment out the if statement and what would be processed if the statement was true. We want to leave the code after the else statement. This will ensure that the quantity field will always be update-able in the shopping cart page. I just commented the said lines out so that reversal is easy:

Code:
<?php
//  if ($product['flagShowFixedQuantity']) {
//    echo $product['showFixedQuantityAmount'] . '<br /><span class="alert bold">' . $product['flagStockCheck'] . '</span><br /><br />' . $product['showMinUnits'];
//  } else {
    echo $product['quantityField'] . '<br /><span class="alert bold">' . $product['flagStockCheck'] . '</span><br /><br />' . $product['showMinUnits'];
//  }
?>