If a headline is changed feedreader sometimes realizes this and aggregates the topics, but it would be a more reliable feature if duplicates are determined based on the article link that is associated with a feed entry, as that's usually constant, even if the headline gets completely rephrased.
Also I wonder if it's a bug or a feature that i get a new entry notification for a smartfeed that searches in google news for certain keywords. every time that serach is executed the results are displayed to me as new. maybe you can fix that with the same approach as above, i.e. remember the links from the last n days and don't show new alerts to entries that are marked read and link to the same target.
oh, and in the new item pop-up window the last line is only displayed half for me, not sure if it's a font size issue, but it's impossible to read the last entry when the box is filled completely or you even have to scoll.