WP.com Imported Images Not Showing Up As WP.org Custom Thumnbnails

[THIS IS URGENT] I am designing a website for my company, and the deadline is SUNDAY, APRIL 15th — I recently imported all posts and attachments from a WordPress.com-hosted blog to our new www.remarpro.com installation. The new site has a featured posts feature on the front page with custom thumbnail sizes. The image links appear to be broken. I regenerated all of my thumbnails using the Regenerate Thumbnails plugin as well as another plugin I have that does basically the same thing. I even reset my permalinks — twice! WHAT COULD BE CAUSING THIS?! Please help.