Jonny, looks like you missed the kernel update. Or maybe just didn't reboot after flashing the kernel, if you used kernel_flasher.

Arjun, as Faheem alluded, extract kernel_flasher into main memory, not the mmc. The mmcs have a vfat fs, which does not permit executable permissions.

In my earlier post, there's a zip. Extract the xrandr file from the zip, and place it as /usr/bin/xrandr, with permissions 755.
I just updated the script in that zip (to the version in this post), so extract it also, place it somewhere, and chmod 755 it, too.
Then invocation as in that post is correct