A problem with modifying and saving questions
I now have an issue with the questions.
It seems that if you modify a previously saved question (multiple choice) it removes the correct answer even if you have it selected when saving.
The result is that the question which is marked as correct before being modified. After being modified, even if the correct answer was selected, at the time of saving it back into the question bank the answer is deleted.
So that when the question is next accessed, even if the correct answer is selected, the submission results in being told that the answer is wrong.
I have verified this by looking into my installations database.
I can create a question (even multiple choice, so long as I don't use punctuation in the remedial content or feedback areas) then save it and it will show in the database as having a 1 in the correct answer.
If I then modify the question and save it the correct answer is changed to a 0.
I couldn't check this on the demo site because I don't have access to your database but I have checked it on two different hosts, same software, same setup.
So could you test this and see what the results are.