Corporate 1.0 for WP3.0 downloaded Jun 7th on WP 3.1.3
On Firefox (and only on Firefox - versions 3.6.3 XP and 3.6.17 Ubuntu Linux 8.04 LTS), MarketPress checkout appears in the sidebar where the shopping basket is and not in the main page. It works OK in IE8, Chrome, Opera, Safari. And it works with the default 2020 theme. It suggests an unclosed <div> or something like that.
A second issue is where the last menu is a drop down. The last submenu does not have the right coloer. It is as if an onmouseover or .hover instruction is not working properly.