Filtering still fails to work correctly most of the time.
An example: I want to block all articles with the tags: bskyb, sky, and skyplus from a feed. I select the appropriate feed's properties and set it to match all conditions and set a rule stating that tag is not one of the following for the previously stated tags. When the feed is displayed it will still display articles with those tags. In some cases it will display articles that have more than one of the excluded tags. In this case all of the articles contain multiple tags including tags that are not listed as excluded (and that's where I think the problem might be coming from).
I'm still only getting one of each article so that problem is fixed, but at present the filtering isn't actually filtering anything out most of the time.