This is by design. A "selected/not selected" can only be true or null. You need to write your own property, possibly inheriting from PropertyNumber, which could store both true and false. I know that this is quite common, especially for dynamic properties. If the value is null, you can present the value in a drop down as "inherits value from parent" along with "true" and "false". /Steve

Thanks for the answer. I managed to create a custom property based on the example in the EPiServer book on page 203 - A drop down list that inherits from PorpertyNumber. I also added an empty ListItem so that the user can clear the value of the property. Everything seems to be working fine now except for one thing - when I change a value and click "save", the value is updated but the drop down list stills shows the old value. When reload the dynamic properies page, the correct new value is presented. Has anyone encountered this problem before? Any ides of what the problem could be? This is the code inside my class: private DropDownList ChoiceDropDownList; public override void CreateChildControls(string renderType, Control container) { switch(renderType.ToLower()){ case "edit": ChoiceDropDownList = new DropDownList(); ChoiceDropDownList.ID = Name; CopyWebAttributes(container, ChoiceDropDownList); ChoiceDropDownList.Items.Add(new ListItem()); ChoiceDropDownList.Items.Add(new ListItem("Yes", "1")); ChoiceDropDownList.Items.Add(new ListItem("No", "0")); ChoiceDropDownList.SelectedIndex = 0; if(base.Value!=null){ switch((int)(base.Value)){ case 1: ChoiceDropDownList.SelectedIndex = 1; break; case 0: ChoiceDropDownList.SelectedIndex = 2; break; } } CopyWebAttributes(container, ChoiceDropDownList); container.Controls.Add(ChoiceDropDownList); container.Controls.Add(CreateParseValidator(ChoiceDropDownList)); break; default: base.CreateChildControls(renderType, container); break; } }