Hi,
I recall another case where someone had to pass arguments containing spaces to the command prompt, which caused problems. The solution was to wrap the arguments in quotation marks:
process1.StartInfo.Arguments = "\"/c voc2wav.exe "+Convert.ToString(shortPathVocLoc) + " " + Convert.ToString(shortPathWavLoc) + "\"";
I'm not sure if it helps in your case, but give it a try.
:)