Summary:
Can't select page content type guestbook when adding new page
Detailed Description:
After upgrading from 1.10.3 to 1.11.2 and updating the guestbookmodule to
1.4_RC2 i can't select the content type guestbook anymore. This problem also
occurs when a fresh install is done with 1.11.2 with the guestbook module
1.4_RC2