No title ?fixme?

Scenario:
1. You add a File-object
2. You enter in type "text"
3. You choose a html-file from your filesystem
4. You upload the file
You can see in ZMI this object with its size. If you look at your file with your browser you see a "normal" html-page.

Then click in ZMI at the object again. You get the upload-form. In the type field is "text". You change this to "text/html". The second input field is empty.

If you send the change of the type to the zope server then the content of the object is cleared without warning.