All of my customers are being undercharged in PayPal by 10-90 cents, because my cart is not including the GST tax on shipping in the total it sends to PayPal (IPN). I have seen some comments on this problem with 1.3.7 and WPP, but I am using 1.3.8 and IPN. Any ideas?

Also, about 1 in 5 orders are not showing up in my admin... I have tried a few changes today after browsing these forums, so we'll see if that has made a difference....