Forum Thread Stealing--It's Becoming an Epidemic
 

On our forums, if person A creates a new thread and person B replies within the first minute, person B's reply appears above the original post. It is so widespread on our forum that it has a name--"thread stealing." Memes have been created. Guides about how to do it have been written. Users are starting to double post every time they create a new thread, lest their thread be stolen.

How can we repair this? What might be causing it?