I had a similar problem, my .bat file wouldn't correctly execute when I had the full file path in the "Program/script" field.
"D:\path\to\file\somebat.bat" didn't execute. (with quotes)
When I put D:\path\to\file\ (without quotes) in the Start in (optional): field and somebat.bat in Program/script: field somebat.bat executed correctly.
Go figure... not exactly sure why having "D:\path\to\file\somebat.bat" in the Program/script: won't work.
Maybe someone could shed some light on that?