How to re-enable older Flash in Safari 5.1.7
In the latest version of Safari, Apple enhanced the browser with a security measure that ensures users make use of the latest version of Flash player. The browser will check for the latest version of Flash, and if your installed version is out of date, then it will disable the plug-in and prompt you to download the latest version, but this might not always be desired.
This security feature has been applauded by Adobe's Brad Arkin, who in a blog posting stated:
"We welcome today's initiative by Apple to encourage Mac users to stay up-to-date: With the Applemore