Bug#617475: Neither ogv nor webm are reproduced accurately

[Jonny]

Mike wrote:
> Can you try with a build from mozilla.org ?
> ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/4.0b12/linux-i686/en-US/firefox-4.0b12.tar.bz2
> 
> (to sort out if that could come from our cairo)
It is the same as Iceweasel 4.0~b12-1.

It confirmed it with past firefox nighty build. The change between
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2010/12/2010-12-15-03-mozilla-central/firefox-4.0b9pre.en-US.linux-i686.tar.bz2
and
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2010/12/2010-12-16-03-mozilla-central/firefox-4.0b9pre.en-US.linux-i686.tar.bz2
is a cause.