We've discovered a simple fix for the missing post function buttons such as quote, edit, etc.
All you need to do is go into your user control panel (button on the top of the right panel, or the User Profile button at the very top of the page).
From there, go to the Board Preferences tab.
Go to the "My language" drop down and select french. Then hit submit.
Now select British English in the drop down menu and hit submit again to go back to English.
Your buttons should all appear once you've switched to French and back. If not, let us know. But this seems to be fixing the problem for everyone so far.
Thanks for being so patient, everyone.