Strange bug!! A simple ListPicker doesn't show it's items when I click it!! What?!?!?!?

Question

Hi guys. I have a bug in my application and I çan't imagine what I could possibly been doing wrong. I have 2 listPickers in my app. If I press one of them, I get the list of regions but if I press the town list picker ("pueblo" in spanish) it dosn't take me to the screen that suppose to show me the towns. I'm doing exactly the same thing with both of them. I already debugged the app and the the listpcker's items sources HAVE the information. I'm not an expert but definitely not a noob either so this whole thing is just fu$#% up or I'm really missing a stupid thing. I uploaded the entire solution in a .zip file if you guys want to check it out. I will waiting for your answers.

Thank you all!

Samuel