*Bump* One more time.
Just people can know this is a real problem, I am also experiencing this issue where when I click on “Invoices”, it says “No posts found” where the invoices should be. Though it still shows “All (2)” and “Published (2)”. So I am unable to go in and edit previous invoices, even though I am able to create new ones.
Before I upgraded to WordPress 3.1, this Invoice plugin worked perfectly.