Well, I found a new set of drivers (the Omega drivers) for my nVidia card. It seems to have fixed the problem. I have played through a couple of 4+ hour sessions and all seems to be well.
Strange that I had to end up with 'Unofficial' 'Unsupported' and not whql certified drivers. And they are an older Version of the drivers. I downgraded from v45.23 to 44.03 in the process.
Oh well, thanks for letting me bounce my frustrations off you.
Cheers!
