Here I am again, problem is solved, it was a dimmer thing. There was a little problem in one of the wires that connect dimmers. Fat frog could manage, but jester was irritated by that. So, Stewart, may be if you check again your dimmer system you might find the reason for the strange situation. Wish you the best!
sorry, stewart, can´t help you, but i got a similar problem: my jester was working fine, but all of a sudden the output is gone. The desk shows me the outputs as normal, but dimmers get no signal. What could have happened to my jester?