luup.variable_get always returning nil?

I have a simple scene that I want to get working. It simply turns on a light if any of the doors are unlocked, and off if they are all locked. However the luup.variable_get is always returning nil. I’ve tried polling the device first, to no avail, as well as pulling the data from the json, which returns 1 if it’s locked as I expected, so I know I have the right requests and IDs… Any help would be appreciated.

Example:
http://LOCALIP:3480/data_request?id=variableget&output_format=xml&DeviceNum=101&serviceId=urn:micasaverde-com:serviceId:DoorLock1&Variable=Status
gives 1 if locked, 0 if not

The LuaUPnP.log says:
LuaInterface::CallFunction_Scene Scene 44 failed [string “function scene_32()…”]:14: attempt to concatenate local ‘BACK_DOOR’ (a nil value)

Code is:
local FRONT_DOOR = luup.variable_get(“urn:micasaverde-com:serviceId:DoorLock1”, “status”, 31)
local BACK_DOOR = luup.variable_get(“urn:micasaverde-com:serviceId:DoorLock1”, “status”, 101)

luup.log("Front Door " … FRONT_DOOR … " Back Door " … BACK_DOOR)

if ((FRONT_DOOR == “1”) and (BACK_DOOR == “1”)) then
luup.call_action(“urn:upnp-org:serviceId:SwitchPower1”, “SetTarget”, {newTargetValue = “0”}, 100)
else
luup.call_action(“urn:upnp-org:serviceId:SwitchPower1”, “SetTarget”, {newTargetValue = “1”}, 100)
end

[tt]status[/tt] vs. [tt]Status[/tt] ?

Yep, that did it. Thanks!