Dictionairy Serialization Problem: Keys and values get lost

So, I've been working on this problem for a while. I have an .asset, derived from a Scriptable Object, that is mainly one float and a Dictionairy. I've been using help from here: http://answers.unity3d.com/questions/460727/how-to-serialize-dictionary-with-unity-serializati.html to serialize my Dictionairy. My keys look like this:

 [Serializable]
 public class Hex : IEquatable<Hex>, ISerializationCallbackReceiver
 {
     public static Hex[] directions = {
           new Hex(+1,  0), new Hex(+1, -1), new Hex( 0, -1),
           new Hex(-1,  0), new Hex(-1, +1), new Hex( 0, +1)};
 
     [SerializeField]
     public int q;
     [SerializeField]
     public int r;
 
     public Hex(int q, int r)
     {
         this.q = q;
         this.r = r;
     }
     public Hex() : this(0,0) { }
 
     //more stuff here
 
     public override bool Equals(System.Object obj)
     {
         Hex h = obj as Hex;
         if (h == null)
             return false;
         else
             return h.q == q && h.r == r;
     }
 
     public override int GetHashCode()
     {
         string s = q + "," + r;
         return s.GetHashCode();
     }
 
     public bool Equals(Hex other)
     {
         if (other == null)
             return false;
         else
             return other.q == q && other.r == r;
     }
 
     public void OnAfterDeserialize()
     {
         
     }
 
     public void OnBeforeSerialize()
     {
         
     }
 }

I've been working on different solutions, but basically what I am trying to do is:

Have a custom editor window that can Generate, Load and Save those Dictionairy-Assets (They're Grid-Maps). I've been using Object-Fields to get my target, then change it, and "set it Dirty", or generate new Assets and copy and paste, but somehow my Map-Objects lose Keys and Values, causing IndexOutOfRange Errors here and there.

Is the problem in my Key Class?

Unfortunately my code is starting to get messy.

I feel like, if that does not work out I just write my own FileWriter that writes the Dictionairy in a textfile and read it out when I need it. It's exhausting, help!

Here's a picture of what I am trying to do: