I have a Dell Latitude E5400 Laptop plugged into a docking station, which is connecting a mouse, keyboard, and monitor (via DVI). When my laptop is on, and I plug into the docking station, about 50% of the time the computer locks up completely. The caps lock / num lock buttons don't change the lights, flipping the WiFi switch doesn't turn off the WiFi lights, Ctrl+Alt+Del does nothing. Only a cold hard power-off will let me keep going.
However, the other 50% of the time, hot plugging works great.