bert,
You're probably spot on about the interference.
Microwaves, the motors in fridges and freezers, large amounts of metal (pots, pans etc), will all contrive to scatter/distort the signal.
But you know what they say, if you can't stand the interference stay out of the kitchen......
(Which reminds me: If you can't stand the heat stay out of the kitchen, if you
still can't stand the heat your house is on fire
)