Some people are experiencing an issue where videos on Web sites that require Adobe's Flash Player are freezing even after updating to the latest version of the full-release Safari 3.2.3 on their Macs. The freezing issue is also happening when using Firefox on the same sites.
"CBS.com videos wouldn't play yesterday, saw there was a new update (3.2.3), downloaded it. Worked fine. Today, all videos freeze Safari and Firefox (CBS, ABC, MSNBC, etc). anyone else having this problem???"Possible solutions
Apple Support Discussions user "hpr3" suggests uninstalling the Flash Player and reinstalling the latest version of Flash Player.
Apple Support Discussions user "Hawaiian_Starman" also suggests repairing permissions:
"Those videos are Adobe Flash driven. With the latest update came an updated Flash plug-in. Until Adobe changes its coding, it's important to "repair permissions" after this type of installation.
Go to your Finder: Applications > Utilities folder. There, open Disk Utility. Highlight your HD on the left, then select "repair permissions." You'll see a number of items filling the screen. No concerns about many of them. What's important is the Flash files are changed.
When done, restart Safari. Go to the Safari Menu > reset Safari. Select "cache" only, then reset."
Read this Adobe KB "How to" article on how to uninstall the Adobe Flash Player plug-in and ActiveX control.
Reinstall the latest version of Flash Player here.