#1 (very minor; only fix if you have absolutely nothing better to do) When previewing comments, the user picture shows as "none" even though I have done.
#2 (normal; somewhat annoying) The forum listing at http://szeged2008.drupalcon.org/forum only shows "1 new" when there are new *posts* not when there are new replies to posts. As a result, I have to keep a mental tally of how many people responded to my forum topics in order to tell if there are new ones.
defaults?
#1: yup, I already noticed this, but not sure where the problem might come from... We certainly do not do custom theming of comments, so I am not sure what might cause this (and have better to do :)
#2: hm, again, we use the default forum module page to my knowledge, so IMHO this should be default Drupal 5 behavior (I don't have unread stuff to check now unfortunately)