"Me gustaría mucho que usted hiciera el trabajo bien."
"I would like it very much if you did the job well." was marked incorrect, but it means exactly the same thing.
It seems that the majority of the questions in this lesson do not accept correct English answers in the subjunctive. Pretty outright stupid, considering that this is supposed to be a lesson about the subjunctive. Please report every error so there is a chance that they are fixed. Note: you may have to copy the "correct" answers to a text/doc file to refer to in order to be able to complete this lesson.