Firefox plugins: where are they now, in 10.1beta3?

Before 10.1 the firefox plugins were symlinks in the firefox/plugins directory. Now, in that directory (/usr/lib/firefox/plugins) there is only the null plugin. Yet, about:plugins shows flash, acrobat, java. How are they located now, in 10.1? I ask because I have a problem with not displaying PDFs from firefox in beta3. In about:plugins there's dragon egg and acrobat reader. But I still don't get any .pdf displayed in browser. I'd like to remove dragon egg/acrobat and see what happens. In any case, it's still a bug.