Think I've nailed this. Won't bore you again with the technical, but let me know if you're still experiencing these large (and I mean several hours, or at least noticeably long period) rollbacks. I'm not interested in the 'I just robbed someone of 20k two mins before restart and it's gone' kinda stuff - just the serious 'I bought two HEMTTs and banked £400k three hours before restart and it's gone' stuff.
Likewise, if anyone gives me the 'I ran into an invisible vehicle and exploded' sidetrack, expect the shaft from me. I'm ONLY interested in failures of the data-sync (manual or auto) here, please, beloved peeps.
I'm really hoping I have nailed this hoary bastard to the wall...