>>>Can you please outline exactly what did you do step by step for dummies? I probably did something wrong yesterday, but it was very depressing to have it coded once, then re-coded again.
>>
>>I created a sub-classed DataGrid:

    class SomeGrid : System.Windows.Forms.DataGrid
>>    {
>>    }

and dragged it from the toolbox onto a form. Here's the generated code:

namespace SmartDeviceProject1
>>{
>>    partial class Form1
>>    {
>>        /// <summary>
>>        /// Required designer variable.
>>        /// </summary>
>>        private System.ComponentModel.IContainer components = null;
>>        private System.Windows.Forms.MainMenu mainMenu1;
>>
>>        /// <summary>
>>        /// Clean up any resources being used.
>>        /// </summary>
>>        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
>>        protected override void Dispose(bool disposing)
>>        {
>>            if (disposing && (components != null))
>>            {
>>                components.Dispose();
>>            }
>>            base.Dispose(disposing);
>>        }
>>
>>        #region Windows Form Designer generated code
>>
>>        /// <summary>
>>        /// Required method for Designer support - do not modify
>>        /// the contents of this method with the code editor.
>>        /// </summary>
>>        private void InitializeComponent()
>>        {
>>            this.mainMenu1 = new System.Windows.Forms.MainMenu();
>>            this.someGrid1 = new SmartDeviceProject1.SomeGrid();
>>            ((System.ComponentModel.ISupportInitialize)(this.someGrid1)).BeginInit();
>>            this.SuspendLayout();
>>            // 
>>            // someGrid1
>>            // 
>>            this.someGrid1.BackgroundColor = System.Drawing.Color.FromArgb(((int)(((byte)(128)))), ((int)(((byte)(128)))), ((int)(((byte)(128)))));
>>            this.someGrid1.Location = new System.Drawing.Point(28, 41);
>>            this.someGrid1.Name = "someGrid1";
>>            this.someGrid1.Size = new System.Drawing.Size(174, 166);
>>            this.someGrid1.TabIndex = 1;
>>            // 
>>            // Form1
>>            // 
>>            this.AutoScaleDimensions = new System.Drawing.SizeF(96F, 96F);
>>            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Dpi;
>>            this.AutoScroll = true;
>>            this.ClientSize = new System.Drawing.Size(240, 268);
>>            this.Controls.Add(this.someGrid1);
>>            this.Menu = this.mainMenu1;
>>            this.Name = "Form1";
>>            this.Text = "Form1";
>>            ((System.ComponentModel.ISupportInitialize)(this.someGrid1)).EndInit();
>>            this.ResumeLayout(false);
>>
>>        }
>>
>>        #endregion
>>
>>        private SomeGrid someGrid1;
>>    }
>>}

Compiles fine...
>
>Does it run fine? I got an error in run-time, not in the compile time. Also what type of the project did you chose for your class?
OK. I got the error - so just implement the ISupportInitialize methods in the base class:

class SomeGrid : System.Windows.Forms.DataGrid ,System.ComponentModel.ISupportInitialize
    {
        public void BeginInit(){}
        public void EndInit(){}
    }

Unless something (like another thread) is trying to access the form during initialization (unlikely) this should work fine.