Thanks, this now gives me something to test and play with today :)
I first started playing with Mozilla just a few months ago. Meanwhile, I've been coming to loath PDF files for various of my own reasons over the recent years. This means that of recent, I've been more prone to avoiding files I find on the web if they are PDF to begin with. Maybe this explains why I have not yet encountered the experience you describe, although it is interesting, in a co-incidence/synchronicity kind of way, that just one night ago the thought came to me "Hmmm, i don't think I've ever tried opening an PDF web page with Mozilla". This happened late at night and I put it off for another day. Perhaps today is that other day.... ?