Problem with product page (sidebar goes down)
Ok, mine is inside an article container. Go to Appearance -> Commerce Kickstart -> Settings -> Zone and Region Configuration and check Content Section -> Content Zone -> Regions.

There should be Sidebar First, Content, Sidebar Second in order. Make sure all of those are in there.

I do know I ran into this issue but mine was CSS related (I changed the width of the content region). Check your settings above and make sure everything looks good. No unassigned regions etc. Try a full wrapper if you don't have one and try without if you do and see if that changes anything.