Took a little sleuthing but I am up and running with 7.9RC on 10240Pro. It seems that both my DisplayLink USB graphics cards did not like to reside in USB 3.0 ports as they did in Win7 Pro. I haven't yet examined if it is a conflict with the AMD FirePro 2100 DisplayPort cards or a problem with the Intel chips on the ASUS X-99A MB; but the easy work-a-round was to utilize the USB2.0 ports for the DisplayLink hookups.
