How can I resolve Fence ReleaseSync error in VR mode?

Hi there,

Anyone know what's up? After a build, I can launch my windows .exe which loads the game into the DK2 and runs, but the view is not stereoscopic and the single view is split across both eyes. When I Alt+F4 out of this game, I get a properly stereo rendered freeze frame of the standard DK2 health warning as if the game is starting, but the exe task has been halted and has nothing in the task bar. When I disconnect the DK2 this screen disappears.

The log shows that the program is getting stuck on an error described as "Fence ReleaseSync"

OVR Error: OVRTime: 1350.181421 Time: 2015-08-04 15:03:03 [308:361:700] Code: -1003 -- ovrError_Timeout System error: -2005270527 (887a0001) -- The application made a call that is invalid. Either the parameters of the call or the state of some object was incorrect. Enable the D3D debug layer in order to see details via debug messages. Description: Fence ReleaseSync

I've tried multiple versions and patches of Unity. I've updated Oculus runtime to 0.0.6. I've rolled back to the GeForce drivers recommended by Oculus. I've tried disabling DX9, stopping, starting, restarting Oculus Runtime, VR mode, Unity... I've tried this with a proper project and with a dummy scene with no scripts or anything. No matter what I do the result is the same. All previous unity demos still work as before.

I'm at my wits end here. I've scoured every forum and on the verge of going back to legacy DK2 integration which worked fine. Any help would be greatly appreciated, I might even buy you a beer!

Thanks, Lance