Default [Q] cant root ME301T

I cant seem to get my ME301T rooted. I've tried various methods and tools. The bootloader is unlocked, but towelroot, motochopper, kingo all fail to root. the exploit is either too old or my 'phone is not supported'.

I'm running 4.2.1 build number JOP40D.US.epad-10.6.1.31-20130823. I'm very interested in getting 4.4 on the device so any help is appreciated.

any ideas?

thanks in advance.

EDIT: I just tried kinjo root from my work PC (Win7) and it worked. It hadnt worked through VM previous.