The Rich Text Editor is known to not work on a few browsers such as Safari and Opera. If you're using one of these browsers I suggest trying to view Clearspace on Firefox.
More than one year after your post and this problem is still present. And I've also noted that the same happens with Google Chrome.
Any idea whether this is going to be resolved in CS 2.0.X? I haven't checked if it's also present in CS 2.5 because we don't use it in our infrastructure.