JPFX: Any ideas to try?
Call Sky. They've come out and installed a new LNB for your multiroom setup, and you're paying them a big handful of money each month to provide the multiroom service, which only works in one room at a time.
AFAIK they provide the gear, and if doesn't do what it is supposed to, they come and fix it. It's all part of the fee you pay each month.