I had MySky installed recently and the first thing I noticed was a rather loud continuous whirring noise coming from the unit. Sounds like it could be the hard drive or a fan. It continues even when the unit is turned off via the on/off button. It is loud enough to be annoying when watching programmes at low volume. Just want to know if this is normal ie does anyone else have this sound from their unit?. I'd ask Sky but would rather hear from users. Thanks.