The way the portal works is quite simple, it looks at the data in the forums you define as portal forums and it grabs the last X ammount of them and displays them as the latest first and the oldest last... it doesn't take into account stickies or announcements, as an announcement or sticky will not always be the last X posted...
The best route of fixing this would be, as you did, editing the template page and adding the information you need at the top.
