Thank you for your post and thank you also to the poster of the post to which you referred.
I am using Windows xp professional and I downloaded and installed Firefox 3.0.8. I decided to try my own Chronicle Text Experiments font that is available on the web as follows.
The following two posts include notes about the font.
Having observed ligature substitution work using just a few words (Actually a distinctive typeface.) I then tried a larger test. The font has quite a number of ligatures.
Here is the source code of the file that I used.
Test Ligatures
Actually distinctive typeface apple copper lock offer field flow office affluent churn change between choose.
Here is a graphic made from part of a Print Screen of the result.
ligatures.png
William Overington