What OS are you using, Windows? If so, what version?
What model of Icy Dock docking station are you using?
Are you using the power from the mother board only, or have a power supply for the Icy Dock itself?
Have you checked the cables and connectors? Some Icy Dock models have had bad cables and connectors.
Are you connecting the dock directly to the PC or through a hub?
Do you have the XFast USB software installed?