Why don't video or audio clips open with RealPlayer on Mac OS X?
When you install RealPlayer for Mac OS X, the installer associates certain audio and video files with it, and it becomes the default media player for any file types you choose to associate with it. If you install another media program after installing RealPlayer, some of these file types may be associated with the new program.
You can re-assign these file types to RealPlayer by clicking the RealPlayer menu, choosing Preferences, and choosing Media Types from the list at the left.
If you download a file from the Internet and want it to open by default with RealPlayer, you can manually associate the file type with RealPlayer. The icons of the affected files will change to RealPlayer icons. When you double-click one of these icons, RealPlayer starts and plays the file.
To manually associate a file type with RealPlayer:
1. Select the file in Finder.
2. From the Finder, go to File menu.
3. Select the Get Info option.
4. Click the drop-down list in the file information window and select Open With Application.
5. Select the RealPlayer and click OK.
Now whenever you double-click a file of the type you have associated, it starts in RealPlayer.