Its a business object... Here is the Class.

 Do you see the problem ? Thanks for the quick response.

using System;
using System.ComponentModel;
using DevID.Framework.Core.Data.LiquidProvider;
using GVG.Framework.Interface;
using Infragistics.Win;
using PropertyChangedEventArgs=System.ComponentModel.PropertyChangedEventArgs;
using PropertyChangedEventHandler=System.ComponentModel.PropertyChangedEventHandler;

namespace GVG.HyperDrive.BusinessLogic.DataObject
{
    public class Personne : LiquidBO, INotifyPropertyChanged, ILiquidBO 
    {
        public static Personne Personne1 = new Personne { Nom = "Mathieu", ID = "M", PersonnePartyType = PartyType.CompagniePartyType };

        public static Personne Personne2 = new Personne { ID = "E", Nom = "Eli", PersonnePartyType = PartyType.PersonnePartyType };

        public static Personne Personne3 = new Personne { ID = "PL", Nom = "Pierre-Luc", PersonnePartyType = PartyType.CompagniePartyType };

        private Guid _personneUID;
        private string _id;
        private string _nom;
        private PartyType _partyType;

        public event PropertyChangedEventHandler PropertyChanged;

        public string Nom
        {
            get { return _nom; }
            set
            {
                if (value != _nom)
                {
                    _nom = value;
                    NotifyPropertyChanged("Nom");
                }
            }
        }

        public PartyType PersonnePartyType
        {
            get { return _partyType; }
           
            set
            {
                if(value != _partyType)
                {
                    _partyType = value;

                    NotifyPropertyChanged("PersonnePartyType");
                }
               
            }
        }

        //[DescriptionAttribute(@""), Bindable(BindableSupport.Yes)]
        //[DataObjectField(false, true, true)]
        //public string UnitName
        //{
        //    get { return _partyType.ID; }

        //    //set
        //    //{
        //    //    if (value != _partyType.ID)
        //    //    {
        //    //        _partyType.ID = value;
        //    //        NotifyPropertyChanged("UnitName");
        //    //    }
        //    //}
        //}

        public string ID
        {
            get { return _id; }
            set
            {
                if (value != _id)
                {
                    _id = value;
                    NotifyPropertyChanged("ID");
                }
            }
        }

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }

        public Guid UID
        {
            get { return _personneUID; }
            set
            {
                if (value != _personneUID)
                {
                    _personneUID = value;
                    NotifyPropertyChanged("UID");
                }
            }
        }

        public string DisplayValue
        {// todo Faudrait caller DisplayValue changed si une des propriétés composant DisplayValue change...
            get
            {
                return _id + " : " + _nom + " (" + _partyType.Description + ")";
            }
        }

        public string TypeAbreviationValue
        {
            get { return "Prsnn"; }
        }

        public void Create()
        {
            Create(this);
        }

        public void Delete()
        {
            Delete(this);
        }

        public void Update()
        {
            Update(this);
        }

        public void Load()
        {
           

            //using (IDbConnection conn = new SqlConnection(Constant.DatabaseConnectionString))
            //{
            //    LiquidHelper.Load(this, typeof(Personne), this, conn);
            //}
        }
      

        public static void Save(Personne personne)
        {
            //using (IDbConnection conn = new SqlConnection(Constant.DatabaseConnectionString))
            //{
            //    if (personne.UID == Guid.Empty)
            //    {
            //        LiquidHelper.Create(personne, typeof(Personne), conn);
            //    }
            //    else
            //    {
            //        LiquidHelper.Update(personne, typeof(Personne), conn);
            //    }
            //}
        }

        public static void Create(Personne personne)
        {
            //using (IDbConnection conn = new SqlConnection(Constant.DatabaseConnectionString))
            //{
            //    LiquidHelper.Create(personne, typeof(Personne), conn);
            //}
        }

        public static void Update(Personne personne)
        {
            //using (IDbConnection conn = new SqlConnection(Constant.DatabaseConnectionString))
            //{
            //    LiquidHelper.Update(personne, typeof(Personne), conn);
            //}
        }

        public static void Delete(Personne personne)
        {
            //using (IDbConnection conn = new SqlConnection(Constant.DatabaseConnectionString))
            //{
            //    LiquidHelper.Delete(personne, typeof(Personne), conn);
            //}
        }

        public static LiquidGenericCollection<Personne> List(Personne personne)
        {
            Personne filtre = personne;

            LiquidGenericCollection<Personne> personnes = new LiquidGenericCollection<Personne>();

            personnes.Add(Personne1);
            personnes.Add(Personne2);
            personnes.Add(Personne3);

            return personnes;
        }

        public LiquidCollectionBase List()
        {
            LiquidGenericCollection <Personne> personnes = new LiquidGenericCollection<Personne>();

            return personnes;
        }

        public override void InitializeChilds()
        {
            _partyType = new PartyType();
        }

        public static ValueList GetValueList()
        {
            ValueList myList = new ValueList();

            myList.ValueListItems.Add(Personne1);

            myList.ValueListItems.Add(Personne2);

            myList.ValueListItems.Add(Personne3);

            return myList;
        }
    }
}