Care to take a stab at it? We'd love to include your solution.

OK, I did a little digging in plugins/serendipity_events_textile/textile.php. It seems that the global variables for the various regexes (regices? ;) ) were not available properly through the globals keyword.

With the following ...

An s9y blog with open_basedir restriction in effect, when selecting to add an image to an entry, PHP complains that file_exists() in serendipity_admin_image_selector.php/line 136 is violating the open_basedir restriction on "/uploads/picture.jpg".
if (!file_exists($file['imgsrc']) && $is_image ...

A blog that runs in non-UTF-8 mode had empty <title>, <content> etc tags in all feeds (RSS 1.0/2.0, Atom 0.3/1.0 etc). All other elements (eg Links, Dates) were present. A newly created UTF-8 blog showed all content correctly. While hunting down the problem, I noticed that the following code was ...