ID:669559
 
Map Instancing by Forum_account
An easy way to create multiple instances of a map. Each instance is put on its own z level.
19 fans · Created Oct 11 2011
BYOND Version:494
Operating System:Windows 7 Ultimate
Web Browser:Chrome 18.0.1025.152
Applies to:this library
Status: Open

Issue hasn't been assigned a status value.
If you have a mob which occupies multiple tiles it will be create as many times as the number of tiles it occupies when a map is instanced.
Thanks for reporting that. It should be an easy fix.
I can verify this occurrence as well.