Okay, those two together mostly accomplish what I need, but I've run into another snag.
The correct answer for one of my problems contains the # character. My custom grader properly checks answers and provides the appropriate feedback (it's just doing perl string compares), but when WW tries to display the correct answer or preview the student's answer, I run into problems.
jsMath tells me "You can't use 'macro parameter character #' in math mode", while images mode just drops the #.
Is there an easy way to tell WW not to typeset answers for this question (i.e. not put the answer preview or correct answer in math mode)?