Preview displays the correct version of the page, but the version information in the sidebar incorrectly shows the latest published version of the object instead of the current draft. This also affects the buttons below the iframe that are used to return the editor to the editing page.
To recreate:

• Create and publish an object
• Edit it, creating a new draft
• Click the "Preview" button in the left sidebar
  The iframe shows the current draft, but the information in the sidebar is wrong and the buttons below the iframe are disabled.