To my knowledge, the URC100 rf is not addressible(the mrf-250 must be on '0' for it to work with rf).

With the 250 in the bedroom set to '0', it will receive the 950 comands regaurdless of the rf setting of the 950.

I don't deal with the URC100 but I think you will have to up-grade to an MX-350 in the bedroom to make this work.

Try removing the antenna from the bedroom 250.
It might make it out of range from the 950 but still work with the 100 in the bedroom.