Error serializing a class to save / load

Hello everyone:

I have this problem: I try to save the current status of a game I'm developing, and this "progress" is written in a Texture2D. Think of it like a MS Paint canvas where you draw things, only it's not :) Even after doing as I was told looking in other answers around here, the final save file is around 1kb, when it should be around 3MB (the texture is quite large).

Anyway, I follow this thread's path, or this different simpler path, and it's still not working for me... There's something wrong with the serializing part, that's for sure.

Here's my code:

 [System.Serializable]
 public class SaveData {
     
    public Texture2D normalMap;
     
 }
 
 public class SaveLoad {
     
     public static string currentFileName = "SaveGame.hur";                // Edit this for different save files
     public static string currentFilePath = Application.persistentDataPath + "/Saves/";
 
       // Call this to write data
       public static void Save (Texture2D norm)          // Overloaded
       {
             Save (currentFilePath + currentFileName, norm);
       }
 
       public static void Save (string filePath, Texture2D norm)
       { 
         SaveData data = new SaveData ();
         data.normalMap = new Texture2D(norm.width, norm.height);
         data.normalMap.SetPixels(norm.GetPixels());
         data.normalMap.Apply();
         FileStream stream = new FileStream(filePath, FileMode.Create);
         try {
             BinaryFormatter bformatter = new BinaryFormatter();
             bformatter.Serialize(stream, data);
         }
         catch (SerializationException e) {
             Debug.LogError("Excepcion al serializar el savegame. Datos: " + e.Message);
         }
         finally {
             stream.Close();
         }
       }
 
       // Call this to load from a file into "data"
       public static SaveData Load ()  {                // Overloaded
         return Load(currentFilePath + currentFileName);
     }   
     
 
       public static SaveData Load(string filePath) 
       {
         SaveData data = new SaveData ();
         FileStream stream = new FileStream(filePath, FileMode.Open);
         try {
             BinaryFormatter bformatter = new BinaryFormatter();
             data = (SaveData)bformatter.Deserialize(stream);
         }
         catch (SerializationException e) {
             Debug.LogError("Excepcion al deserializar el savegame. Datos: " + e.Message);
         }
         finally {
             stream.Close();
         }
         return data;
     }

That's only a sample, it's actually bigger but that's the part that's failing, I'm quite sure of that. For more information, right now I'm getting this error:

Excepcion al serializar el savegame. Datos: Type UnityEngine.Texture2D is not marked as Serializable.

This is captured in this "try":

 try {
     BinaryFormatter bformatter = new BinaryFormatter();
     bformatter.Serialize(stream, data);
 }
 

...while saving in the method Save.

I've read (here) that Texture2D is a Serializable type of object, so this is weird to me... I'm using unity 3.4, windows 7 x64 and this is written in c#, but the script that makes the call to "Save" and "Load" functions is in JS.

Any insight in this please? Any help would be GREATLY appreciated!

Thanks!