Yahoo Music videos do not work
From MozillaZine Knowledge Base
Yahoo! Music (aka Y! Music aka Y! Launch aka Launch.com) officially requires the use of Internet Explorer to view its videos. Contact them and ask them to support Firefox and Mozilla Suite.
Fortunately for Windows users, there's a workaround. (This doesn't work for Launchcast Radio, just for the music videos.)
- Install Windows Media Player and its Mozilla plug-in.
- Install Greasemonkey and restart.
- Install the pkLaunch script into Greasemonkey.
- Activate Greasemonkey (click on the sad monkey face on the status bar).
You should now be able to access the videos.