Check your Nano, if you have the one with CH340 usb chipset will not work for serial gateway. It will work if you use it for a node. Need to get another nano with FTDI chipset for serial gateway and it will work. I have the same problem and even try many different ways still won't work until I figure it out from the other post. You don't need to buy the one for $35 bucks, search on Ali.... you still find some sellers sell Nano with FTDI chipset for @ $7 bucks. Hope it help and save your time.
@stofakiller Try to find Arduino Nano with FTDI usb chipset, the problem is on the Vera's firmware usb driver not happy to work with CH340 usb chipset ( most of the clones Arduino is build with CH340 for cost saving I guess ) .
@sundberg84 yes, you are right, CH340 chip works fine with arduino IDE but will not work with Vera Edge controller if you use it as serial gateway sketches, the reason is Vera Edge controller's build in USB driver not compatible with CH340 chipset.
For those newbies like me, don't waste your time to check anything if you able to see your serial gateway in IDE serial monitor " Gateway started " . Adopted from the original poster Burtonian, I am able to make it work last night follow the information in there and use additional USB to TTL converter device with FTDI chipset something like this one
http://www.aliexpress.com/item/1pcs-FT232RL-FTDI-USB-3-3V-5-5V-to-TTL-Serial-Adapter-Module-forArduino-Mini-Port/32256920717.html , attach 4 wires from this add on USB converter to your Arduino Nano as follow:
FTDI - USB Arduino Nano
VCC ------------------------------------------ 5V
GND ----------------------------------------- GND
RXD ------------------------------------------- RXD
TXD ------------------------------------------- TXD
Connect USB cable from Vera Edge controller to USB port on FTDI - USB (not Nano). Check back on Vera plug-ins you will see you gateway is there. I'm able to connect from the first try. Hope is help for somebody still frustrated like me couple days ago 
. Thanks again Burtonian, I'm very appreciated.
Check your Nano, if you have the one with CH340 usb chipset will not work for serial gateway. It will work if you use it for a node. Need to get another nano with FTDI chipset for serial gateway and it will work. I have the same problem and even try many different ways still won't work until I figure it out from the other post. You don't need to buy the one for $35 bucks, search on Ali.... you still find some sellers sell Nano with FTDI chipset for @ $7 bucks. Hope it help and save your time.
Hi Burtonian, thanks for your helpful information, I'm new also and have the same problems with the clone nano Arduino for serial gateway. Could you please share more info about how you connect 4 wires from FTDI unit to serial gateway with CH340G chipset, thanks a lot.