WD 15 Dockings Enterprise Issue

Good Morning, im writing beacause we have some of ours WD15 Dockings that have something wrong.

When we turn on the pcs (5580-5480 with windows 7) with the dock already plugged, they slow the entire system make it laggy.

We tried everything, including the update of pc bios and docking firmware, without success.

If we turn on the pc without the dock and plug it after the boot,(when its already in the desktop) the system is stable.

We have a lot users with this issue.

Hoping for a reply :D

Bye