Are you aware of issues with the KRIESI ENFOLD Theme and your WP HUMMINGBIRD Plugin?
On this page, http://www.hearthsidefoods.com/careers/, we are using a background image on scrolling elements. (This effect is used throughout the site - this is a good page to use for trouble-shooting.)
When the WP Hummingbird Plugin is enabled, all the elements with this background image "disappear". From what I see using trouble-shooting tools - Hummingbird is changing the CSS and hidding the elements.
I can set-up a test/dev site for trouble-shooting - but before I do this I thought I'd check with you to see if this bug/conflict has already been addressed.
(working for Carl Melville/TMG)