coupons not working in vm298a joomla333

[seyi]

Ok, so I have:
- joomla 3.3.3
- virtuemart 2.9.8a

2 issues:
I could not get coupons to work until I changed

Code Select Expand

$_db->getEscaped(

to

Code Select Expand

$_db->escape(

In file www/components/com_virtuemart/helpers/coupon.php


Second issued:
- I add a coupon to the cart
- it displays the discount and code correctly
- then I update the product quantity from 1 to 2
- the coupon code is still displayed but the discount amount has disappeared

How can this be resolved?

Thanks