I don't understand the question. When I typed cgminer -V like you asked, it returns cgminer version 3.12.0
Type in "which cgminer" without the quotes it should return /usr/bin/cgminer
It does.
No idea, I'd repeat the process.
I already tried it about four times. I even restored the firmware a couple times, just to be sure.
Edit: I was able to get it updated to 4.2.0 by using the other version instead.