ckeditor strange behavious

I've started testing ckeditor 0.3.1 and get some strange behaviour when I click the button for Bold text:
i.e. Erroneous characters appear.
Now if I delete the erroneous characters and add some txt I get an error on save:
Any ideas on what this is?
i.e. Erroneous characters appear.
Now if I delete the erroneous characters and add some txt I get an error on save:
Any ideas on what this is?