One annoying thing that happens regularly is “Planet Flooding”. This is when one of the many blogs that is syndicated by a public Planet installation changes it’s time stamps and has 10 or more old posts appear as new. It’s doubly annoying when the blogger in question knows about the problem.
Planet Flooding is easy to solve. If you are changing your blogging software or doing something else that may result in old posts appearing to be new then all you have to do is configure your blog to include a small number of posts (maybe two or three) in the RSS feed. Seeing two old posts re-appearing plus a new post explaining it is not going to annoy anyone.
If you run a Planet (or Venus) installation then configure it to have a maximum number of posts per feed. For a Planet that syndicates feeds from a number of individuals and only includes a few days of traffic (which is probably a category that covers most Planets) there is no need for more than four items per feed.
For a severe case of Planet flooding (EG posts which always appear as being the newest and are therefore at the top of the list) the thing to do is to immediately remove the feed until the problem is fixed. Allowing a broken blog configuration to annoy other people is not doing any favors for the blogger in question, it simply drives people to filter the Planet to exclude the articles by that blogger. Yes it does take some work to adjust the configuration of the Planet, but that is surely no more work than replying to email rejecting requests for the configuration to be adjusted.
The first aim of running a blog or a Planet should be to make it readable, Planet flooding breaks this for the Planet and for the blogger who caused it. It is a technical problem and needs a technical solution (which can be temporarily removing the blog from the Planet syndication list).