Jan,
I tried both front and back ports and nothing positive. It is possible that the BIOS is corrupted and cannot read any of the ports. I considered using the 2.0 USB ports on the inside header, but the pin spacing is 2.0 mm rather than the typical 2.54 mm spacing of a USB 2.0 port on a motherboard. Without a proper 2.0 mm connector to USB 2.0 female, the two inside ports are worthless.
I gave up trying to use that particular D54 and exchanged it for another. I used the same memory, but changed the SSD and the USB cable on the optical drive. I plugged the mouse and the keyboard into the Front USB connectors and the Samsung optical drive into the lower USB port on the Back.
When I powered this D54, The BIOS setup (F2) immediately recognized the Samsung Optical drive. I set that a #1 in the boot order, saved the changes (F10) and let it restart.
Windows 7 loaded without any problems from the Samsung and it appears to be going through its startup ritual.
Thanks for helping
Carl.