Here's a workaround (not the world's best, though): When Toutatis reaches
EOL, change the repository entries in /etc/apt/sources.list to
http://oldarchive.trisquel.info/trisquel toutatis main
(and of course, do the same for toutatis-security and toutatis-updates)
since the Toutatis contents of archive.trisquel.info would be moved there by
then.
You won't get any updates then, though, and I don't think packages will be
patched, etc. That's why I said that it isn't the world's best. (Anyway I'm
typing this from a newly installed and updated Trisquel Dagda)
Still, as lembas said, I think you should first run "lspci" and post the
results here.