well not the greatest programmer but basically here is my code all works fine and dandy yet if there is an update to the table while the Gallery Menu is open then she give me a 'Improper Argument Error'using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using ESRI.ArcGISExplorer; using ESRI.ArcGISExplorer.Application; using ESRI.ArcGISExplorer.Mapping; using ESRI.ArcGISExplorer.Geometry; using ESRI.ArcGISExplorer.Data; using ESRI.ArcGISExplorer.Threading; using WRMS.AVLDataSetTableAdapters; namespace WRMS { public class AvlGallery : ESRI.ArcGISExplorer.Application.Gallery { #region Fetch Data private AVLCurrentResourcesTableAdapter AvlTableAdapter = new AVLCurrentResourcesTableAdapter(); private AVLDataSet AvlDataSet = new AVLDataSet(); private int fetchCount; #endregion #region Icons Image t6resource = WRMS.Properties.Resources.T6Resource; #endregion public AvlGallery() { this.AvlTableAdapter.Fill(AvlDataSet.AVLCurrentResources); fetchCount = AvlDataSet.AVLCurrentResources.Count; avlGalleryFill(); } public override void OnClick(GalleryItem item) { AvlInfoWindow avlInfo = new AvlInfoWindow(item.Caption.ToString()); avlInfo.Location = ESRI.ArcGISExplorer.Application.Application.ActiveMapDisplay.ConvertToScreenPoint(ESRI.ArcGISExplorer.Application.Application.ActiveMapDisplay.Center); avlInfo.StartPosition = FormStartPosition.Manual; avlInfo.Show(); } public override void OnUpdate() { base.OnUpdate(); if (AVL.isChecked) { this.Enabled = true; this.AvlTableAdapter.Fill(AvlDataSet.AVLCurrentResources); if (fetchCount != AvlDataSet.AVLCurrentResources.Count) { this.Items.Clear(); avlGalleryFill(); } } else { this.Enabled = false; } } public void avlGalleryFill() { foreach (DataRow resource in AvlDataSet.AVLCurrentResources) { this.Items.Add(new GalleryItem(resource["Callsign"].ToString(), t6resource)); } } } }I am guessing that it would not be wise to alter the GalleryCollection while the Gallery is open????any suggestions??