Some of you may have come across a web page that links to or has embedded a media file that no longer plays. You could swear it worked before you updated to iTunes 7, but now it’s not. Instead you are seeing the faded QuickTime Logo with a question mark. Do not worry, your not going crazy. It did work.
When you install iTunes 7, to get full functionality, you also have to install QuickTime 7.1.3. With the installation of QuickTime 7.1.3, or even QuickTime 7.1.2 for that matter, a small plug-in is installed in your Internet Plug-Ins folder. The QuickTime plugin.plugin is most likely the root of your problem. To fix, just navigate to the System’s /Library/Internet Plug-Ins folder. This is the root level folder not your user folder. Move the QuickTime plugin.plugin to the desktop and restart your browser.
What you should now see is the QuickTime Logo (above) that is replaced by the control bar (below) once your media loads.
If that does not work, you may also try removing the VLC Plugin.plugin from the Internet Plug-Ins folder.
Hope this helps.