Newbie: cannot connect to VR3

Hello,

I'm new to Arduino and just went through some basic samples with a Nano, all fine. My general idea is using Arduino for Home Automation and so I added the Voice Recognition module VR3.1.

I can upload the sample sketch provided vr_sample_train.ino but I get no response from the VR when trying to send commands, zip, nothing. Switching Tx and Rx gets me a "check system settings" response. The yellow LED on the VR is constantly ON.

What may I have done wrong?