Like Ismo, I have a strategy to avoid duplicate threads.
I check first, then open a new thread and slam a BB code straight from Flickr and post. Then I check the thread list again, and if there's still no other thread for that day I edit the post with the back story, technical details and maybe a bonus image.
If I discover an earlier thread for that day, I delete the post in my thread and post it in the older thread. In the old days I left a message in my thread to ignore it, then asked Mar to delete my thread. Now I and Pepperberry Farm have moderator privileges, it's even easier