Problem with CKEditor

In my Drupalinstallation i have different roles with different permission to node types. I use the module content_lock for the authors of a book. But if i activate the option "Use javascript to detect leaving the node form" the editor (CKEditor) if node is editing, doesn't load. If I dectiviate the option CKEditor load.
Drupal: 7.17
CKEditor: 7.19
Maybe ther is no problem with other Editor, but i can't change them.