I checked this several times.

It sounds like all is fine once you enable the Profile (mandatory!) link in your menu.

If not, you need to give more information for this problem, since it's different from the original problem caused by not following the CB installation instructions (having the mandatory menu link). See my signature for the information needed for proper diagnosis.

After a lot of unsuccessful experiments I changed to TinyMCE, profiles (mandatory) and set the menu item and profiles to public. That seems to be stable now. As a result I agree that the problem was an unstable access to FCKEDITOR.