Okay, after much irritation, it seems that there's an issue with weapon types. Scimitars seem to lock an activator, and are prevented from removal. Although katanas are custom weapons, the more standard types seem to work well. The blades katana has big problems, as does the Dragonbane. Most of the vanilla weapons are okay, with a couple exceptions but I can't remember what they were off hand. Bear in mind that custom or modified weapons appear to give the most problems regarding plaques and racks. Hope this helps some of you.