DynamicDataStore refuses to add new properties

Hi!

I am really stuck at something. I am trying to add a new property to an existing DynamicDataStore, but if I do, I get a nullreference exception on 

the get store call:

DynamicDataStoreFactory.Instance.GetStore(typeof(T))

My class looks like this, and I am trying to add the PluralName property:

    [EPiServerDataStore(AutomaticallyRemapStore = true, AutomaticallyCreateStore = true)]
    [EPiServerDataContract]
    public class Ingredient : IDynamicData
{
(...)
      [EPiServerDataMember]
      public string PluralName { get; set; }
}

I have tried to add an initialization module that remaps the store, but no luck.

What am I doing wrong?