If you are having a problem getting past the ITHR problem message I found that clearing the CMOS settings by shorting the jumper on the MoBo gets you past this error condition you might have to unplug the USB devices also but I have not had to.
We have over 1000+ GX280s with the Dell FP170X (1702-1704) monitors working in the field and I have only seen this problem twice and not heard of any others from my coworkers, so this seems to be a very rare problem.
As I said I hope the A06 BIOS update fixed this systems problem, it is working for now.