Hp USB 2.0 Docking Station and HP ProBook 6540b FREEZES

[probleemos]

Laptop: HP ProBook 6540b /w Win7 Pro
Docking Station: HP USB 2.0 Docking Station " AY052AA#AC3 "
20" LCD Screen

Problem: Sometimes picture freezes, mouse cursor doesn´t move anymore. (Laptop connected to Docking Station. Laptop cover closed, picture showing only in LCD screen).

Solution: Open laptop cover and wait that picture come to laptop´s screen. It works now - able to move coursor. And when you closing cover again, picture comes back to LCD and it works again.

What might be problem and how i can fix it?

I have updated docking station and graphic card drivers..