On Lynda.com I hear audio, but don't see video

Skip Taylor reported on drupal.org:

I wanted to see the video quality so I tried one of the free demo tutorials. There's audio and a green background. I have the latest QuickTime installed and using Firefox 3 with the QuickTime plug-in. Should there be more to this than a green background?

Indeed there should. :) Lynda.com gave him the following steps, which solved the problem:

I had to change a setting in Quicktime 7.5:

1. Open the QuickTime Application
2. Go to: Edit > Preferences > QuickTime Preferences
3. Click on the Advanced tab
4. In the Video section (midway down in the window), select the option for Safemode (GDI only) instead of DirectX
5. Restart the browser.

Please comment here if that doesn't work for you.