ST-E2 Transmitter Question

Does anyone use the ST-E2 or a 580EX II to trigger remote flashes? Lately I have been haveing some difficulties with my Pocket Wizards not firing all the time, and Im looking at other options for remotely fireing the flashes.


Questions:


1. Does an umbrella block the signal outdoors?


2. How much if any does the sun interfere with the signal?


3. Do other eletronic devices mess with the signal?


So those are the three main questions I have. Im looking more towards getting another 430EX II instead of the ST-E2 sense I already have a 580 and the ST-E2 is only a few bucks cheaper then the 430.


Thanks


Joel

1. Depends upon how thick it is. At least if ambient light is rather intense, it probably would.
2. If the sun is shinging directly into the slave's receiver, it's not going to work. If you can shade the sun, it may work anyway.
3. No, since the signal is light only.