I’m copy-pasting a blog post from blizzard, as we had a conversation on IRC about using the video tag on Firefox and Dreamhost hosting (due a problem with my other blog (in Spanish)):
A quick note if you’re going to be using OGG open web video hosted on web servers. There’s an important configuration change that you should make so that Firefox recognizes it as video. In my Apache configuration I’ve added this directive:
AddType application/ogg .ogx
AddType video/ogg .ogv
AddType audio/ogg .oga
Most web servers are likely to return the mime type as “text/plain” which Mozilla will not show as video. If you don’t set it, and it’s served up as text/plain then Firefox is likely to show either an error or endless buffering. (Although I suspect that the endless buffering is actually a bug in our internal player and will likely be fixed.)
Update 2: You should look at this post from Silvia for the correct information. Thanks, Frank.
Anyway, you should follow the original post, as it could be updated since the publish of this post.
And I have sent an email to Dreamhost support to get a global support for .ogv files. I will post the decision as soon as I’m getting the answer.
And we must try the 
