Hooray!! My SanDisk Ultra 30Mb/s Class 6 card (from Costco) now works perfectly! Thank you dom
I initially had high hopes for this card because it had fast 4k random R/W test results with CrystalMark, so I was disappointed when it was the only card out of 7 other cards that didn't work.
But now it does work and early tests show it is living up to its promise... for example power-on to logon prompt is less than 20 seconds! That's 7 seconds faster than any of my other cards.
The bad news however is that with the kernal.img and start.elf files from 30 May, EVERYTHING is running by default at a much lower resolution than 1920x1080 (more like 800x600) plus when I start GDE my mouse and keyboard do not work.
If someone could tell me if I can fix this myself that would be great.