No 'Safe to Eject' notice

I have implemented a UMDF driver which works fine except for one niggle.

When I select ‘safely Remove Hardware and Eject’ for the device it goes through the process of unloading the driver, but I never see the ‘It os now safe to remove your device’ message.

In the Device Manager it says that the driver has been ‘prepared for safe removal’.
If I just unplug the device it disappears and there are no apparent issues with this, but I would like the message to be displayed.

Does this mean that I have missed something from my driver?
If so, any ideas as to what?

Thanks in advance,

Peter Young