Typing don't work on a encrypted authentication screen

Hi,

We have a problem with a Dell Ultrabook. When the computer is rebooted, at the EEPC authentication screen, typing the password on an external keyboard don’t work until the user moves the mouse back and forth.

I’ve asked two other user’s with the same ultrabook and dock station and they don’t have the problem.
If the computer is cold booted or if is not docked, the problem don’t appear.
I’ve tried pluggin a different mouse and keyboard with the same result.

Endpoint Encryption for PC : 6.2.1.315
Agent EPO 4.6.0.1694
Dell E7440 Ultrabook, A08 BIOS
Dell Dock Station E-Port PR03X
Windows 7

Bios config :