Without looking too hard, I'm not sure if this is an Opera problem or an Observatory problem - the fact that it works in FF, Chrome and IE9 mitigates towards the former, the fact the Opera 11.x generally has very good CSS and JS support mitigates towards the latter.
Without looking too hard, I'm not sure if this is an Opera problem or an Observatory problem - the fact that it works in FF, Chrome and IE9 mitigates towards the former, the fact the Opera 11.x generally has very good CSS and JS support mitigates towards the latter.