For some reason, after having done some world trimming, we are getting random items appearing. When we try to break the items either we just get a local DC, or worse case we get a full server crash. I have identified it as being at least partially the fault of Witching Gadgets both by crash logs, and because disabling witching gadgets not only causes the items to go away, but no other muckery occurs.

Examples of strange things spawning are graves from Graves Mod where torches use to be, Mirror on the Wall from Thaumcraft spawning in the middle of nowhere. When you try to right click, or left click (harvest) you either suffer a local DC, or a full blown server crash. http://pastebin.com/tTwYv0e6