I've recently seen a new bug appear on a site running WP e-commerce. New products (or certain existing products) get stuck as 'drafts'. Once they are marked as draft clicking 'publish' does not do any good, and the only way to make the products publicly accessible is by directly editing the entry in the MySQL database.
UPDATED Further investigation shows that this is not an wp-ecommerce problem - it affects all posts.
Switching to twentyten theme fixes the problem, so clearly the inability to publish must lie somewhere in the custom theme I'm using. Seeing as it's my own theme, I guess I'm to blame ;-)
Error reporting throws up a mention of an incorrectly called register_script() function, however I don't think this is what's causing the problem, as it's not in my code.