It is always the best thing you can do to completely uninstall the old version of the Flash player and then proceed with installation of the new one. Even though new installations are supposed to remove the old version and then install new one, sometimes, especially Flash plug-in installations for browsers are acting kind of weird.
I don't have problems on either of my browsers, not on PC nor on my Mac. IE7, Firefox and Safari, all three have the latest version of Flash installed without any problems.
Oh... forgot to mention Flock... no problems there either.