If you are using the latest versions of Safari, QuickTime, and Flip4Mac to play .wmv movie files in Safari, you may notice that once you play a movie, the performance of your computer degrades. If you open up the Activity Monitor, you'll see that once you play a .wmv file in Safari, Safari takes up 100% of the CPU. Even when the movie is done, even if you navigate to another page, even if you close Safari, it still takes up 100% of the CPU.

I found that by going back to a previous version of Flip4Mac, this problem gets fixed. In my case, I went back from 2.2.x to 2.1.3 and this completely fixed the problem. If you want to revert to a previous revision, here's how to do so:

1 - You need to uninstall your current Flip4Mac installation. You can do this by going to Applications -> Flip4Mac -> Flip4Mac WMV Uninstaller.pkg. Once you select this, you will be guided through the uninstall process.

2 - Get version 2.1.3 of Flip4Mac. If you don't still have it on your computer, you can get it here: http://www.flip4mac.com/wmv_previous.htm. Once you download it, go through the normal installation procedure.

Once you reinstall Flip4Mac, Safari will no longer take up 100% of the CPU when playing .wmv files.