bonus points if you want to share the reason why you had a misconfigured sources.list file (maybe we can improve / avoid that somewhere)
I had the problem on one of my relays because I was running "apt-get update && apt-get upgrade" which had the update part return an error because the tor-experimental-0.3.3.x source now returns a 404, so upgrade was not called
so you are saying you where stuck at 0.3.3.5-rc because you didn't have all the lines in sources.list?
the interesting part would be, how did you end up with that configuration since the official documentation is clear about it. Did you use a 3th party guide? if so could you point us to it?