This problem has been occurring intermittently since early November despite the fact that during this time I have kept Firefox and all my plug-ins up to date. It happens intermittently, so I have not been able to recreate it in Safe Mode. I don't use Firefox for anything other than visiting that particular site, but even on that site it doesn't appear to happen in the forums section. Only on specific pages (which relate to particular games, as the site is a risk-based board game site).

I have listed the most recent Crash ID below, but there are a lot more that I can provide if necessary