I assume you have the dial on the MRF-250 set to any number except 0?
If so, it's hard to say what might have caused the temporary interference. Could be a remote stuck on or another device transmitting the same frequency in your house or a neighbors. For example, I had a similar problem where someone placed a heavy object on a remote located in the household that pressed a button and caused continuous RF transmission. Also I've noticed that the MRF-250 will hang up occasionally and needs to be power cycled.