Yes, I like to run the official self-updating build from https://ftp.mozilla.org/pub/firefox/nightly/latest-mozilla-c... , because it's the official build (which is appreciated when reporting bugs) and always fresh.

- You could switch to that too (I run it even on my job Ubuntu machine, never saw any benefit to using the official Ubuntu PPA apart from proper packaging, which I don't care about, this Firefox lives in /opt/firefox and that's okay with me, and getting updates are a matter of hitting Help -> About, easy).

- Or just wait a few days for the PPA to serve a fresher build. EDIT forget about this and read bzbarsky's answer above. Thanks, Boris :)