My solution to totem issues is to deinstall it and definitely don't use it's plugins. It always crashes somehow...
At least on Fedora12, the gecko-mediaplayer is a more modern player-plugin for gnome. I use
"gecko-mediaplayer-0.9.8-2.fc12.x86_64 : Gnome MPlayer browser plugin." ALso gxine-mozplugin-0.5.903-4.fc12.x86_64.
Both work well with google-chrome-beta-5.0.375.29-46008.x86_64 and netscape. I use chrome.
Due to their better integration with ALSA (I can explicitly set toslink digital out instead of using generic
/system/gstreamer/0.10/default/audiosink like gecko mediaplayer), my current favorites are the Qt-based smplayer ( smplayer-0.6.8-1.fc12.x86_64 ) andf the kde-based kmplayer ( kmplayer-0.11.2a-1.fc12.x86_64 ).
All seem to play the LAC 2010 videos well.