I have the same problem on my dell XPS 15 esata port.
It has a HM67 chipset and worked fine under 11.2
Please fix this intel as I just upgraded to windows 8 and would like a whql certified driver to be compatible with my machine.
So... actually this is Dell's problem @@?
Does anyone has have this problem, too?
So it seems... I also created a thread at the dell support website: Intel RST 11.5 and 11.6 no longer support esata on dell motherboards - Disk Drives (HDD, CD/DVD, Blu-ray) Forum - Disk Drives - Dell Community
Dell will probably respond with "use the driver that we published" but hey you never know!