Until my upgrade to 21, I was able to play videos in WebM format. Now the browser doesn't report the capabilities.

I tried several methods to confirm that:

• Youtube (http://www.youtube.com/html5) reports that the Video Element is partially supported, but none of the formats
• The simple Video Check in W3Schools (http://www.w3schools.com/html/html5_video.asp) reports that Video is not supported
• Quirksmode (http://www.quirksmode.org/html5/tests/video.html) reports that none of the formats (MP4, WebM, Theora) are supported

Please advise in how to proceed.