This question has been answered by donshakespeare. See the first response.
What extra did you install that lets you use TinyMCE?I installed flexibility5 which needs a few dependencies, here's the full list:
TinymceWrapper has chunks for your to edit. You will be looking for the chunk to the specific area you want (introtext, content etc) -> find toolbar:"code..."In the meanwhile I was experimenting with the original TinyMCE plugin which works good but looks bad.
For proper assistance, read the support thread (post your any more questions there)