Is there a bug or virus in this website's software?

I keep seeing strange things happening on this site. Such as long time gaps in a list of threads, in which apparently all posts made during that period have disappeared from the list (though sometimes they reappear later). Also, I just made a new post in another section, and saw it accepted and added to the thread, but the thread wasn't bumped to the top of the list in that section.

I think there must be somthing wrong with the software. Has anyone ever checked into this?
Thank you

 

Database Issues, the threads would appear after sometime..