Somehow, the LNBs are powered by a receiver. You may be blocking the power with those Powermaxes. I don't think that all 3 coax protection circuits are designed for sat signal. Perhaps if you could figure out which lines are delivering power to the LNBs, you could make sure to use the sat coax protector for those lines.

If your signal is completely blocked, check the above. If it's just too weak to lock:

Otherwise, if it is just an amplification problem, I think amping between the LNB and switch is the best idea. I'm not an expert on this part, but I think the 180-457 is more appropriate since it deals with the 13/17 volt difference in the wires from a dual LNB.