obsure problem

[Gary]

We have recently had 2 orders go through without calculating shipping costs.
The item is not set up for free shipping and other orders of the same
product calculate shipping just fine. We use USPS for shipping and we add
$0.50 handling charge so when USPS doesn't respond the order prints a
statement about that and still adds the handling fee.

Has anyone else experienced this? If I go in and try to order the same
product, I get a message requiring me to pick a shipping option before I can
procede with the checkout.

This is very perplexing and I would like to figure out what combination of
events allows it to occur.

Any ideas would be appreciated.

Gary
www.freebears.com