Kurzer Auszug aus dem Changelog:
The method of keeping track of whether to delete old articles changed in NewsFox 1.0.4. Unfortunately, the updater was incorrect. Feeds that were marked not to delete old articles became feeds that would delete old articles including unread articles. So avoid NewsFox 1.0.4 if possible. If you have installed 1.0.4, check your feed settings. This is the only change between 1.0.4 and 1.0.4.1.
Mehr dazu gibt es hier:
http://newsfox.mozdev.org/rss/2008.html#nf37
Das Update kommt wie gewohnt automatisch.