"Distribution boards" aka Power-strips
While a power-strip will kill powerline communications performance, it will if you plug in a bunch of other equipment (e.g. PCs, set-top boxes, routers, etc.) The switching power supplies make a nasty noise.
A good solution is to use a "pass through" PLC adapter (I have this http://www.leacom.fr/niv3uk-pays59-id66-Powerline_NetSocket_NetSocket200+_Euro.html). The pass through has a filter so anything plugged into it will not affect performance. Also, you get your power socket back do might not need a power-strip.
Biting the hand that feeds IT
