Don't install beta versions of directx on your system unless your a beta tester, developer, or just love having to reinstall windows every so often.

DirectX9 is complete overkill for my limited system. For that matter so is DirectX 8 but I do have a few games that require it.

Patches to plug the various DirectX versions' security hole are available for download from Microsoft's TechNet Web site, and users can also retrieve the fix from the standard Windows Update site.