Hello all,
following error occured when we try to order completion.
We're sorry. An error occurred while processing your order that prevents us from completing it at this time. Please contact us and we will resolve the issue as soon as possible.
Thanks and Regards
shyam Prakash pal

After reading your post, I've tracked down the uc_cart-watchdog log entries. The entry before the empty-cart line was the same in both cases: "Page not found: /cart/themes/(...).js". I've fixed this by using an absolute path (/themes/(...)) for the javascript. We'll see if it works..