So it seems like the new discussion-threading system (aka "D2", according to the preferences page) no longer works for me.
I had just gotten used to it -- in particular, being able to click on comments to expand or collapse them -- and suddenly at some point this afternoon I reloaded a page and the whole thing just went away. I'm back to the regular discussion style, where clicking on the title of another user's post will open that post in a separate page.
However, I still have the new style selected in my preferences. I'm just curious whether this is a global problem or something specific to my network or configuration. I've tried disabling AdBlock and some other relevant FF extensions but no dice.
Anyone else noticing anything amiss?