I think there are a bug with the geocoder sample (in titanium studio).
Your version use google map V1. It works, but it is depreacated and some features are not accessible. For using google map V2 you have to do 2 changes according to my post: http://developer.appcelerator.com/question/164411/google-maps-v2-is-different-with-alloy#answer-278090
Your online documentation seems to be good: http://docs.appcelerator.com/titanium/3.0/#!/api/Modules.Map.
The bug is only present with Alloy. The classic mode works perfectly.