So it turns out that you have to specify the path (at least in my case) when creating the ProcessBuilder object (versus changing the working directory later).
If you create the ProcessBuilder object first, and then try changing the working directory, apparently the program is still going to try to run from wherever the ProcessBuilder object was created, unless you specify the path at that point. If that really is the case, then in all honesty I just don't understand what the point of changing the working directory is. I mean, isn't it completely useless? Can somebody please explain what it actually DOES? It doesn't do anything for me... I don't mind, as long as there's a way to run programs outside of the current directory (which I finally found), but I just want to know what is really happening behind the scenes of ProcessBuilder. I've googled this to death, and can't find any clear cut examples (you've gotta admit, the examples from Sun aren't the best).
So... what's VAR1, myValue, OTHERVAR, VAR2, and suffix? Am I really just completely missing the point here, or can somebody else testify that this example is pretty confusing? I need more documentation...