I had the same problem (no port available).
I noticed that on the latest firmware upgrade (0.0.7 b281) you have to manually install arduino-dock package with command
opkg install arduino-dock
then I could see the network port, but I still couldn't flash the sketch to arduino dock.
so I reflashed bootloader, but it only worked with 2nd method (with ICSP header)
after that everything worked out for me.
I hope this helps.