There are possibly two issues here, or one issue both related to the same cause, I suspect they are bugs though. The first is that courses restored from v1.9.x are being opened for editing, but the TinyMCE toolbars are not opening. The type in the drop down box is either HTML format or Moodle auto-format but there is no display. The editing area is not resizable, so I am wondering if there is something in the course that is calling for the previous HTMLArea editor and not TinyMCE. So would this mean there is a trivial fix for it? I suspect this issue has been around for a while, as this discussion, http://moodle.org/mod/forum/discuss.php?d=195250, suggests. The discussion also suggests the issue is related to the backup process.

The other issue is that in some courses, both restored and newly created, the TinyMCE editing box is so large that the resize handle in the bottom right corner, indeed the entire right end of the editor, has disappeared off the screen.

I am not sure if this is the same issue, or if they in any way related at all, as there does not seem to be a link, but there might be. Some courses do not display the toolbars but are fully contained on screen. Some courses the editing area is too large but have toolbars showing, and some courses have both issues. Any help here would be welcome.