Hey Jeremy The AttributeInspector comes with a default skin(which decides the look and feel of the component, part of the new Flex 4 skinning architecture). The default skin is available with the api download(has the delete button). You can write your custom skin which just removes the delete button and apply that skin to the AttributeInspector. If you are not already familiar, you can look at : http://www.dynaplex.com/devnet/flex/articles/flex4_skinning.html?devcon=f4b Hope that helps.
