Just a heads up for the dev team:
While working on e-Commerce for a client I came to the conclusion that the
options VARCHAR column's 255 limit, in the
wp_wpsc_checkout_forms table, is way to short.
When creating a lot of options for a custom <select> field for the checkout things would get cutoff on the database and unserialize() wouldn't be able to do it's job, returning nothing.
This may be fixed by removing that column's set Length.