Hey Mark,
I'm running almost the same setup here, with the exception of upgraded processors and video card (I've got a 5,1 w/ 2X 3.46 GHz, and a 7970 GPU), and I don't have any similar issues.

It's kind of a long shot, but I'm curious... have you upgraded to a metal compatible GPU, or are you still running the stock 5770 ?
I know from dabbling with a couple of Hackintosh builds I've been involved with, that sometimes the graphics card can cause some ioreg funkiness in Mojave.

- Jay


MacPro 5,1/12 core@3.46GHz -- OS X 10.14.6 -- ATI 7970 -- 32 Gig RAM -- Crucial 500GB OS SSD -- Samsung EVO 1TB Audio/Sample SSD -- BIAB 2023 -- Logic Pro X -- Cubase Elements 11 -- Too many plugins