Have you tried holding the emitter away from the device to make sure that it is not an emitter positioning issue? Sometimes a position slightly offset from the receiver is better than directly on top of the IR receiver on your device. You could also try using the variable IR outputs and adjust the output if this is your problem.

Although I don't believe this is related to your issue I would definitely recommending addressing each device to a specific IR port in CCP if you have not done so already. It is also a little easier to debug this way because you can see that you are sending signals to the correct device.