We should start taking votes on what the solution will be.So this is what 1+ support have just sent me.
"Andy Zhang (OnePlus)
Aug 07 02:04
Hi Deuse,
We've recently realized that all OnePlus One devices have this problem, and we're actively working on a solution to fix this. As a temporary workaround, if your phone is plugged in via USB or the headphone jack is plugged, earthing is no issue. Sorry for the inconvenience!
- Andy "
So they admit it's a fault and in my opining they can't fix it.
![Stick Out Tongue :-p :-p](/styles/default/xenforo/vbSmilies/Normal/tongue.gif)
My money is on a new back.