It seems that as a new mean against trackback spam, several blogs tend to use HTTP redirection for Trackback URL endpoints. Serendipity did not yet support this, since it didn't follow any HTTP header redirections.
This has been changed in recent snapshots of Serendpity 1.0-alpha, were we now utilize the PEAR HTTP::Request class to send trackbacks, which is able to follow HTTP redirections. Together with the plugin for sending manual trackbacks to specified URLs, this now allows you to again trackback to any blog that supports trackbacking.
Please have a try with those recent nightlies, if you are currently experiencing problems with sending trackbacks!
The other news is about the Gravatar plugin. A fellow user, Mattsches, sent me a patch for a favatar plugin (avatar icons based on the commenting user's homepage URL favicon). I took that one and implemented it into the existing gravatar plugin, which is now able to support both Gravatars and Favatars. It even uses a fallback method to use the other avatar type, if the first one failed. And of course it caches the results, so that your blog does not need to open many outgoing connections.
- N U M B - New Urban Music Blog am : Favatars