Unity Editor Not Updating to 4.3.3

I’m trying to update Unity to 4.3.3 so I can use the new Sample Assets, but it won’t let me update. I click on Help > Check for Updates, but it just gives me a message saying “The Unity Editor is up to date. Currently installed version is 4.3.2f1.”

I can’t find a manual download for an update file. Is there another option aside from uninstalling Unity and downloading the latest version from the website?

I had this problem it the past, my solution has been a manual download and install.