If Bob's suggestion to trash preferences doesn't work you might try trashing your InDesign cache files. This can often be helpful for problems within panels.
To do so:
On Windows 7 and above the caches files are hidden. To find them go to the Control Panel and open Folder Options and then click the View tab. Then select “Show hidden files and folders” or “Show hidden files, folders or drive options” in Advanced Settings. Then delete (or rename) the folder at the end of this path: C:\Users\[User Name]\AppData\Local\Adobe\InDesign\Version [#]\<Language>\Cache.
I'll try it