Titanium has lots of pitfalls, hope they will disappear in nearest future.
I just spent some hours on finding out why my Titanium app won't build for android. The reason is that you can not use non-alphabetical letters symbols in translation string names and event spaces. This mean that you should have L('hello_world') instead of L('Hello World') in your multilingual crossplatform mobile app.
One more thing: you probably should use $1..$2 as translation string placeholders on Android instead of %s, %d. I haven't check this but found while googlin.