Unity PHP Database is going haywire

In the script I created below, AddPlayer() works perfectly and adds both strings to the database accordingly. However, AddUser() throws out an "500 Internal Error".

Notice that the only difference between the two coroutines is the url inserted, one using "addUserURL" and the other using "addScoreURL". Also note that BOTH urls are exactly the same. Is there something I'm not seeing here?

 private string secretKey = "scoreBat"; // Edit this value and make sure it's the same as the one stored on the server
     public string addUserURL = "http://www.danalbuquerque.com/scoreDatabase/addScore.php?";
     public string addScoreURL = "http://www.danalbuquerque.com/scoreDatabase/addScore.php?"; //be sure to add a ? to your url
     
 
     void Start()
     {
 
     }
 
     IEnumerator AddUser(string name, string password)
     {
         //This connects to a server side php script that will add the name and score to a MySQL DB.
         // Supply it with a string representing the players name and the players score.
         string hash = Md5Sum(name + password + secretKey);
 
         string post_url = addUserURL + "name=" + WWW.EscapeURL(name) + "&score=" + WWW.EscapeURL(password) + "&hash=" + hash;
         //string post_url = addUserURL + "name=" + name;
 
         // Post the URL to the site and create a download object to get the result.
         WWW hs_post = new WWW(post_url);
 
         yield return hs_post; // Wait until the download is done
 
         if (!string.IsNullOrEmpty(hs_post.error))
         {
 
             Debug.LogError( hs_post.error);
         }
         
         
     }
 
     IEnumerator AddPlayer(string name, string password)
     {
         //This connects to a server side php script that will add the name and score to a MySQL DB.
         // Supply it with a string representing the players name and the players score.
         string hash = Md5Sum(name + password + secretKey);
         
         string post_url = addScoreURL + "name=" + WWW.EscapeURL(name) + "&score=" + WWW.EscapeURL(password) + "&hash=" + hash;
         //string post_url = addUserURL + "name=" + name;
         
         // Post the URL to the site and create a download object to get the result.
         WWW hs_post = new WWW(post_url);
         
         yield return hs_post; // Wait until the download is done
         
         if (!string.IsNullOrEmpty(hs_post.error))
         {
             
             Debug.LogError( hs_post.error);
         }
         
         
     }