Really ackward Poll problem with my vbulletin 2.3.4

[Aaron1]

In forumdisplay.php the thread starter is the one who started the poll and the thread, that's normally ofcourse... But the problem I have is that the first person that replies to that poll & thread, he will become the thread starter in the forumdisplay threads list. And that shouldn't happen ofcourse.

You can view the problem in 'action' here:
There is a thread (in my poll section) called: Which nationality of prince fans is the most? As you can see "ivy1213" is the one that started the thread/poll:
http://www.housequake.com/showthread.php?s=&threadid=26135

But when you look at the forumdisplay the first person that replied (hoinszj) is suddenly the thread starter:
http://www.housequake.com/forumdisplay.php?s=&forumid=31


Does anyone remember this problem, or can push me into the right direction to fix this?

Thanks people!

[Aaron1]

Nobody has an idea what it could be? Or recognizes the problem?

Pointing into the right direction would be very helpfull too! :-)