After upgrading to WP 3.3.x (I'm now using 3.3.1) the visual editor in posts wasn't working anymore. You can see more details about the behavior on this thread:
After deactivating FBLike plugin everything came back to normal.
Installing the plugin on a fresh WP install didn't trigger the same behavior, so I tried to narrow down the circumstances. The theme I was using didn't make any difference (tried with Twenty Eleven theme having the same result). I also deactivated all plugins except FBLike and still having the same issue. The only plugins that couldn't be deactivated were Login LockDown and HostedClientService that are compulsory at my host (page.ly).
Let me know if you need any further details from my setup, I'd be glad to offer them to you for fixing this issue.