Could you list a sample of the data in the houses table. Just the top 5 rows is good. I'm thinking that DISTINCT is working just fine. So... Press711 did steer you right in the thread you referenced.
If you have data like this...
id - area
1 - uptown
2 - uptown
3 - downtown
4 - downtown
then the query "SELECT DISTINCT id, area... " will return all rows. So my next question is, what other data is in that table. A short table dump would help us to see what's what 🙂