Dell Latitude E6410 problem with backlit keyboard when using Eport

Dear colleagues

On my laptop above, I have just installed a new backlit keyboard to replace the old (non-backlit) keyboard. 

The good news is that the backlighting works perfectly.

Once the laptop has been placed on the docking station, one can still type with the new keyboard. However with it on the docking station the backlighting is not working at all. Whatever I do; with it on the docking station there is no backlighting. As soon as I release it from the docking station the backlighting is operational again.

Please does anyone have similar issue with solution or can anyone provide some advice or solution. I would like to be able to use it on the docking station with backlighting operational

With thanks, 

Ian