In FileMaker 13, you can open layout setup and disable that option.
With older versions, you don't have that option.
"one version behind" is often the perfect place to be. You may not have that latest greatest feature, but you are using a version that's been through the "bug fix update process" to a point where you are reasonably certain you won't get "surprised" by a project killing bug.
But FileMaker 13 may prove to be the exception. While WebDirect is having its share of "teething troubles", FileMaker Pro/Advanced 13 has been remarkably free of major "new version" issues.