I started having the same problem. If everyone is still following this try turning off the overdrive (button on the gear shifter) and try it then. Mine stops when i turn off my overdrive.
One of my mechanice friends suggested the overdrive sensor should be replaced. Also the transmission fluids and fliters should be changed because it might not be getting access to enough fluids where filter is blocked. either way turning off the overdrive seemed to fix it in the short term. Still need to find the problem.