After some system updates this evening, firefox can no longer handle the html input encoding for the elog. I'm not sure what happened. You can still use the "ELCode" or "plain" input encodings, but "HTML" won't work. The problem seems to be firefox 17. ottavia and rosalba were upgraded, while rossa and pianosa have not yet been.
I've installed chromium-browser (debranded chrome) on all the machines as a backup. Hopefully the problem will clear itself up with the next update. In the mean time I'll try to figure out what happened.
To use chromium: Appliations -> Internet -> Chromium