Where the en-US template has a \ to escape a single quote: _('Are you sure you want to renew this patron\'s registration?') ...the translated templates are double-escaped: _('Are you sure you want to renew this user\\'s registration?') This causes a JavaScript error which breaks further JavaScript processing on the page (like toolbars, menus, etc).
*** This bug has been marked as a duplicate of bug 6574 ***