Information Box Dismiss Button Not Working

I run several websites and so far so good on the update to 3.5 except for one. It updates fine but when I go to create a new post, the information box that talks on creating image galleries is on the top left-hand corner and I cannot dismiss it. Putting a screenshot in to show you what I mean.

It causes certain buttons to not function.

https://wp.me/a1TEgY-5jG