Reading the installation instructions on a set of 12V downlighters from a well-known DIY store today, I came across this jem :
This product is designed to operate at safety extra low voltage (SELV) and as such under no circumstances should an earth be connected to it. If earth wires are present then they should be connected together using good quality insulation tape to ensure the continuity of the protective conductors.
How happy would you be if the earth conductors in your house were only held together with insulation tape (good quality or otherwise?!?!).
I had found a socket had been removed in the kitchen at the property I was working on this morning, and the live, neutral and earth wires had been connected together using nothing but insulation tape and guess what - no continuity on the ring on any of the conductors. Not a big surprise really...
PS - thanks for the UBB info Paul, hopefully the quotes will work when I post this!