Canopus
3
Avast 2014.9.0.2006
avast! Online Security 9.0.2006.53 plugin for Firefox
Firefox v 24
Windows XP SP3
Zone Alarm basic.
Issue is definitely related to avast! Online Security 9.0.2006.53 being active.
NB: The above version of Avast program was rolled out a couple of days ago.