I would take the CPU back out and put it back in to rule out any issues with the CPU communicating with that slot.: Done this - still nothing
If its a screw on type cooler: it is
make sure you don't overtighten: its in-between loose and tight but it is in properly
So you also have an i7 coming in that is compatible with the motherboard but its not here yet?: Yes, in the UK here we have stupid posting dates, I bought it yesterday - it's coming around the 29th this month. FYI it's an i7-3770K