view not saving

i create a FEED view, SAVE . OK

i select format RSS FEED - FIELDS - (i don't fill in any values) - SAVE - dialog comes back unsaved, with star/asterisk next to FEED* and the message:

"* All changes are stored temporarily. Click Save to make your changes permanent. Click Cancel to discard your changes."

I've tried various combinations of filling up the fields - but even so it doesn't change the fact that i cannot save the view.

Core 7.12
Views 7.x-3.3

There are no log messages