I've just spend a while looking at this. Here the quick answer:
Add in the following lines before pulling 214 high.
echo 261 > /sys/class/gpio/export 2>&1
echo high > /sys/class/gpio/gpio261/direction 2>&1
echo 1 > /sys/class/gpio/gpio261/value
Now the long answer will take more time than I have right at this moment, but it's something to do with the status of some of the pins that need to be set to a valid configuration before the analog pins will function. It's mentioned somewhere in the Emutex Muxing guide, but I need to spend more time at it to give a good explanation.
Rgds,
Dave.