Dave, I'm going to have to say it is very likely the ECS board. There are very good reasons we have recommended against them here over a span of many years. It's a shame you didn't vet your system here before you bought the components.
I believe this is the only X58 board that jdeb highly recommends:
Newegg.com - ASUS Sabertooth X58 LGA 1366 Intel X58 SATA 6Gb/s USB 3.0 ATX Intel Motherboard