Trouble Reading a Shared Object

I’ve been getting this error when trying to read from an SO:

Correct: NaN Incorrect: NaN

The code I’m using:

try {
    var getFinalExamSO:SharedObject = SharedObject.getLocal("FinalExam", "/");
    var correctCount = getFinalExamSO.data.CorrectCount;
    var errorCount = getFinalExamSO.data.ErrorCount;
    trace("Correct: " + correctCount + " Incorrect: " + errorCount);
} catch (error:Error) {
    trace("SharedObject Error:"+error.toString());
    return;
}

The SO is written with this code:

                // Declare the SO one time for this conditional:
                finalexamSO = SharedObject.getLocal("FinalExam", "/");
                // Write updated "CorrectCount" data to SO:                       
                finalexamSO.data.CorrectCount++;
                finalexamSO.flush();
                //The close() call is a must, otherwise you may experience some Flash IDE crashes
                finalexamSO.close();

(There is similar code for IncorrectCount). Does anyone know why I’m getting a NaN error?