I've created a custom usercontrol so that members can edit there information in the front-end.

I have a few issues though. When saving the fields, I get an error saying

[NullReferenceException: Object reference not set to an instance of an object.]
   umbraco.editorControls.BaseTreePickerEditor.Save() +65
   Kmostarter_MemberCtrls.usercontrols.EditProfiel.UpdateMember_Click(Object sender, EventArgs e) +653
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +153
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3690

Is there any information on how to build a proper usercontrol like this page with example code?:
http://umbraco.org/profile/edit-your-details

When looping through all the properties of the logged in member I translate each umbraco datatype to a webcontrol like:

Control propertyfield = df.DataEditor.Editor;
                                    switch (propertyfield.ToString())
                                    {
                                        case "umbraco.editorControls.textfield.TextFieldEditor":
                                            TextBox txtbox = new TextBox();
                                            txtbox.ID = df.DataEditor.Editor.ID;
                                            txtbox.Text = df.Data.Value.ToString();
                                            txtbox.CssClass = "kol-30";
                                            editControls.Controls.Add(txtbox);
                                            lbField.AssociatedControlID = df.DataEditor.Editor.ID;
                                            break;
                                      ...
                                    }

The problem is that I have a few custom dropdowns in the membertype which is used,  with predefined values. But I don't know how to translate this Umbraco datatype in a proper webcontrol. And how to translate a tinymce editor into a multiline textfield.

Thanks in advance.

grts,

Kim