smart panel selector not working

I am having issues with a selector field on a smartpanel. It has the right values when i click the eyeglass, but when i select one, it comes up and then disappears. any ideas on what i did wrong?

           #region Customer
           [PXInt(IsKey = true)]
           [PXUIField(DisplayName = "Customer")]
           [PXMergeAttributes(Method = MergeMethod.Merge)]


           [PXSelector(typeof(Search5<BillOfLadingLine.customerID, LeftJoin<BAccount, On<BillOfLadingLine.customerID, Equal<BAccount.bAccountID>>>
                  , Where<BillOfLadingLine.truckNbr, Equal<BillOfLadingLine.truckNbr.FromCurrent>>, Aggregate<GroupBy<BillOfLadingLine.customerID>>>)
               // , typeof(BAccount.acctCD)
               //, typeof(BAccount.acctName)
               // ,SubstituteKey = typeof(BAccount.acctName)
               )]
           public virtual int? Customer { get; set; }
           public abstract class customer : PX.Data.BQL.BqlInt.Field<customer> { }
           #endregion







<px:PXSmartPanel LoadOnDemand="True" Height="400px" Width="400px" runat="server" ID="pnDelivery" Key="DeliveryDacView" AutoReload="True" AutoRepaint="True" ShowAfterLoad="True"  AutoCallBack-Target="fmDelivery">
        <px:PXFormView Width="100%" ID="fmDelivery" runat="server" skinid="Transparent" Datamember="DeliveryDacView" dataSourceID="ds">
       <Template>
	<px:PXLayoutRule ColumnWidth="XM" LabelsWidth="S" runat="server" ID="CstPXLayoutRule34" StartColumn="True" ></px:PXLayoutRule>
	<px:PXSelector SyncStateWithCommand="" DisplayMode="Value" CommitChanges="True" runat="server" ID="CstPXSelector36" DataField="Customer" ></px:PXSelector>
	<px:PXTextEdit CommitChanges="True" runat="server" ID="CstPXTextEdit38" DataField="Recipient" ></px:PXTextEdit>
	<px:PXTextEdit CommitChanges="True" runat="server" ID="CstPXTextEdit35" DataField="Comment" ></px:PXTextEdit>
	<px:PXTextEdit CommitChanges="True" runat="server" ID="CstPXTextEdit37" DataField="Email" ></px:PXTextEdit></Template>
</px:PXFormView>
		<px:PXPanel SkinID="Buttons" runat="server" ID="pnDeliverybtn" >
			<px:PXButton DialogResult="OK" Text="Save" runat="server" ID="btnDeliveryOK" ></px:PXButton>
			<px:PXButton DialogResult="Cancel" Text="Cancel" runat="server" ID="btnDeliveryCancel" ></px:PXButton></px:PXPanel></px:PXSmartPanel></asp:Content>