Well I see birthdays on the 29th of August in your calendar and the Birthdays island is empty.
You might want to clear cache in the ubb control panel.
Or sometimes you need to kick start them by ftp. Go into the cache folder and delete all of the files except for the index.html file. That will force ubb to rebuild all of the files.
Before you go down that road also double check file permissions are okay. You can check in the UBB control panel at
cp>>permission checks.
Click on any line in question to expand the display.
