There was one day when I rearranged a couple of threads, feature announcements, bug report, feature cancellation addressing everything in the new feature thread, that may have been part of it.
Also the AGI category is always marked with a new posts icon, just because I can't really check for a cookie from Chris's site to turn it off. Also the thread title in that recently changed but held no relevence because I'm pulling it from another sites rss feed, testing it until Chris comes up with making the rss feed, if everybody thinks this approach is good enough, no one has added their opinions

Beyond that since it opened, I have been tinkering testing and editing my posts and the scripts constantly, some of you may have even seen my errors, but none of that should influence anything about new posts, unless editing posts changes the new post icon, but I don't think it does. All I can say is that except for some minor editing to the members profile in posts, to include awards and arcade stats and then to incorporate Chris's rss feed maker into these forums providing a similar fake board on his own site. I'm hoping he'll make that part anyway, I made the display

There isn't much else script editing on the horizon.
I haven't ever noticed it myself, but if it persists, let me know as my script editing is definately winding down. So if it continues, it isn't because of me editing scripts, but before now, I guess its entirely possible.
I also stickied a couple of threads, as I plan to add to them giving each category its own resources reference like with the sci sytax and listing all of the known resources for them. I stickied one of Omer's threads in the game section because it had game related links on it that I had no idea about so I figured it was a good starting point. If that is an example of what you meant.
Or even it could be, the sci syntax board has two more child boards inside of it, sci how tos and template fixes. It could be the new posts were in those but because of the new post icon you thought you were looking for it in the first board level when it was actually further in.