UPS shipping charges disappear with refresh

[pupil]

I'm having a shipping calculation issue with a client's site where the shipping is calculated correctly when an order is entered, but if a user refreshes their browser on the order confirmation page (checkout_confirmation.php) the shipping amount calculated by weight disappears and the order is passed through with no shipping charges (or in this case, with only the Handling Fee specified in admin). I'm using a mod'd version of OscMax 2.0 with a custom theme based off of the stock theme 'Compromise'.

Buy motorcycle leather apparel at discount prices

I've tried reinstalling the software and have attempted reproducing the problem on other client's sites who also use UPS but I'm unable to make the shipping disappear, so it seems to be tied to the way I have this particular site configured.

Has anyone run into or have a solution for this problem?

[pupil]

the issue can be reproduced in the stock aabox theme as well. So it doesn't appear to be tied to my customized template at all.

Best I can tell (and I'm still kind of a noob at this) is that it has something to do with the session variable not retaining the product weight information on refresh.

[michael_s]

See this:
r1060 - oscmax2 - osCmax - osCommerce Maximized - Google Project Hosting