Ok, so there was a minor sql bug in the main index.php that would slow down rendering of read items in the main page, mea culpa.
The bug was introduced between version 0.3.6 and 0.3.8. If you feel like your gregarius installation has gotten noticeably slower after you upgraded to 0.3.8, this is probably why, and you are encouraged to replace your index.php file with a fixed version, straight from cvs (make sure you’ve got a backup copy of your original file first!)
Fixed index.php.