I'm already not using my ISP's DNS I'm using OpenDNS.

Doug, I'm not complaining about not being able to view Flash, I'm trying to figure out why an otherwise plain h.264 video which is being served by YouTube through a blog embed with HTML5 suddenly requires Flash when I click the attached link to instead display it from the YouTube site.

Interestingly, the message telling me that I need Flash is inside an HTML5 video container.

Tom, thanks for the suggestion for the YouTube5 plugin - installed and working well. If I check the video with that plugin, I get sound on the embedded version too. Also, curiously, checking the info shows all the available sizes and only the smallest 240 version is listed as FLV.

If there were ads requiring Flash, wouldn't that also prevent an HTML5 external embed?