I have the same problem as this thread and would like to fix since its happening to me also
this is the feed I'm trying
If I put the dates at the bottom and manually update it will not work.
If I take out the dates and manually update works fine.
this is on a fresh test blog install
I also put in the word the in Any of these words filter
(a button to get all posts would be a nice feature)
here is what my form looks like