On this site...

[kaamaru]

If I reply to my own topic it appears in updated topics page (http://www.simplemachines.org/community/index.php?action=unreadreplies).

[Norv]

Not for me. However, if I edit my own post/reply with quick edit, later, then it does appear, yes, in unreadreplies.
The issue was reported here too: http://www.simplemachines.org/community/index.php?topic=367930.0

Thank you for the report. It seems it may have been partially solved for the next version.