Hmmm… this appears to be specific to a machine I was using. Apologies!
Whatever it was, the buttons came back!
I have that same issue on Chrome & FF… I’d love to have a solution.
If I enable the plugin, all the “advanced” buttons in the TinyMCE toolbar disappear (more, spellchecking, advanced options button, other custom buttons…).
I have that same issue
Actually, the issue you describe is quite different from the one I describe.
That’s why the forum rules encourage you to start your own topic!
http://codex.wordpress.org/Forum_Welcome#Where_To_Post
Aside from that, posting into a thread that has been marked resolved is unlikely to get you the support you desire.
You’re right, I’ll create a new topic.
Edit : In fact, after further investigations, the issue is not caused by this plugin, but by “WPMU Prefill Post”.
But the issue only appear when both plugins are active… I guess the issue is on the other plugin.