Articles doesn’t update correctly. Database corrupted?

Something very weird happenend. My blog’s
http://www.turkku.com/blogi/

articles do not update correctly any more. The only ones that are shown on first page are from May 2005 (!). As you may see.

And the same goes on with the Administration Panel. By clicking “Manage” there will be shown only (15 latest) articles from _2005_. Thank God, the drop-down list works, so it’s possible to find right (latest) articles and handle them.

AFAIK, everything else (archives, plugins etc) works fine. The problem is that this index.php (?) file somehow is digging 2005 stuff instead the newest articles. That’s why I had to make a stupid additional link to this 2005 article “Uusin blogini”, just to make it possible to readers to somehow get the right one.

I haven’t done anything unusual. It just happened one day. And as I’m a poor newbie with PHP, I don’t have a clue how to resolve this problem. So I have to ask these two basic questions:

1. Is there perhaps some individual code file broken?
2. Is the database somehow corrupted?

I would very much appreciate any help!