I've been playing around with regular Tor, compiled from source (as opposed to TBB).
I've found that while accessing regular websites works fine hidden services don't work at all. For instance, accessing the duckduckgo hidden service yields:
Server not found: Firefox can't find the server at 3g2upl4pq6kufc4m.onion.
I have Firefox configured to use the SOCKSv5 proxy localhost:9050.
When I access Are you using Tor? it says "Congratulations. This browser is configured to use Tor.".