Since upgrading to 2.5.5, in the Template manager screen, all the links have the same template group ID in them, so I can't switch between template groups. It works in Firefox, Opera, and even in IE, just not Chrome. Wondering if anyone else noticed this?
I'd suggest reuploading the control panel theme files from your 2.5.5 install. Perhaps something was corrupted on upload. The files are stored at: /themes/cp_themes/.
Also, make sure the page has completely loaded in Chrome before clicking on the template group.
Also, check the Chrome Dev Tools Network Panel for any 404 errors.