I'm having the similar issues with the D54250WHKH detecting my ssd. I'm trying to use a OCZ Vertex 2 60gb drive. The NUC will not always see the drive. I have successfully installed OpenELEC on it and had it boot and work correctly a few times, but then nothing. I also tried installing Windows 7 and 8 (both 32 bit and 64 bit) and the Windows installer won't install to the drive saying "We couldn't create a new partition or locate an existing one 0x80300024"
I am able to use a regular 2.5" 250GB 5400rpm hard drive without any issues with any OS, so its doesn't seem to be a hardware issue with the NUC. I've also tried downgrading the BIOS as suggested in another post, but it didn't help me.
The OCZ drive is working fine in other computers. It's very frustrating, I've spent most of the weekend trying to figure it out. :S