Paul,
I note on the case, the brand of US Robotics, is this a US made product designed for the UK market?
Second question,
How hard was it to open the case?, I remember posting a thread about these devices some time ago and the problems I had with actually getting the plastic case open to investigate what had happened to the power supply unit on my cordless drill charger.
I note that yours actually has screws in it, not the common plastic welding.