That sounds good!, I think you should check your plugin and make sure the ids are deleted from that object, it seems like this code should do it not sure why it wasn't cleared when you deleted all users.
Or leave it as a reminder to anyone else that runs into similar issues with leet forums. Both work. All the informations in this topic. Or to summarise:
We don't support it.
We can't help.
leet.cc for leet forum issues.
