with regards to inconsistent auto grader

hello guys, I want to share nasty experience with DOM course on javascript. I had lot of predicament of pitfall with auto-grader with php and C#, but it's self-effacing with DOM on javascript. on one of the code challenge with DOM, I provided answer something like ..('#.. li').. but auto grader was adding extra ) something like )) to my answer that I never typed in during entire sleepless night. on following day, I switched to window 7 laptop to to type in same answer, but for surprise, the auto-grader didn't add freaking extra ) to my answer that I type in with window laptop to eventuate to pass the code -challenge. but I got abominated by this kind of nasty diabolic prank to give up the entire DOM course. I already completed javascript course with code -academy of which courses are on succorance on auto-grader. I will dejected with treehouse, but I want to give it a final try before go with different online schools such as Edex or Udacity. can anyone give me wise advise thanks