Tales from the toolroom

The title gives it all away, but at the time I was sitting there wondering why the signal was non-existent over a range of about 20ft, and line of sight too. There were no other devices using the same frequency that I could find so I just happened to notice the pretty pattern of things like fridge magnets attached to the site of the system case - there were a dozen of them looking at me like dead sheep's eyes, and they all took some effort to remove; once that was done the signal strength went back to where it should have been.
Nice little earner there, but I was surprised that this would have such an effect. Did not seem to have any effect on the PC otherwise either.