#8 — TinyMCE interface absent when creating a page

Noticed, in a Plone site now upgraded to Plone 4.0.5 (inci. TinyMCE 1.1.9), that when creating a new page there is no TinyMCE interface for editing the body text, just a simple textarea.
Also (but not sure if related to the above), the selected text format is Plain Text -- although enabled in the Plone Markup setup section, I'd expected the default to be HTML, since I selected text/html as default in that section.

After selecting HTML as the text format and saving the page object for the first time, when one edits the page again the TinyMCE interface does show up.

Wondering if this could be related to raptus.multilinguagefields, I created a new Plone site in a separate instance, now with Plone 4.0.4 (TinyMCE 1.1.8 included), and raptus.multilanguage{plone,fields} not enabled at first. In this case, TinyMCE was not replaced by a textarea when creating pages. But, after enabling the raptus add-ons, I saw the same behavior as above.

Could this be related to changes introduced in TinyMCE 1.1.8? http://plone.org/products/tinymce/ Lacking time to test again with older releases, but maybe (though not completely sure of it) this didn't happen a couple of months ago, before the last couple of Plone upgrades (to 4.0.4 & 4.0.5). Also, I only tested this with Page objects.