Hi Mohamed,
My sincere apologies for the delay in getting back to this problem. I've now tried your suggestion of one-step checkout, which I couldn't actually do because there seems to be a limit of 4 actions per step. Even so, a two step checkout like this
1. Login, Address, Shipping, Terms
2. Cart, Payment, Status
seems to be working so far. And in fact, I think I like the look and flow of this version better!
Because the original problem wasn't a major one, and because the first couple of fixes weren't quite right, I continued to develop the main site with the original plug-in. Could you now provide me with the version that is installed on the test site, or a more recent version? I'll install it on the live site and continue testing.
Thanks again!
Dave