This bug has been fixed in version 1.0.1 on the Windows Phone Store. Please update to fix the problem.
On the Windows Phone version, sometimes the Storage Menu fails to respond and also won't disappear when backed out or switched to another menu. We are working on a permanent fix for this problem and should have an update posted by December 2nd. In the mean time, there is a workaround:
Fix Storage Menu:
After opening the Storage Menu for the first time, if it doesn't respond or gets stuck on the screen, you can make the Storage Menu work again by tapping Menu, then Manage, then Storage another time. On the second time, the menu should function properly as well as go away properly when the back button is used or another menu is selected.