When I try and do the checkout without account thing it brings up the following error:

1062 - Duplicate entry '7' for key 1

insert into customers_info (customers_info_id, customers_info_number_of_logons, customers_info_date_account_created) values ('7', '0', now())

[TEP STOP]
the shop is up at www.hudsonfashion.com

It's a straight-up MS2 Max install, no extra modding (though of course I've played with the admin stuff a bit.