uhm it should only install 1... However i think i know what your problem is.
I am guessing in the past you have disabled some loopback adapters. When you disable them they are still there, so let's say you disable 1 then start SoulMS, it will create a new one and enable the one you have disabled before. So if you disable like 5 of them and you start up SoulMS, all of a sudden you will have 6 loopback adapters running. You need to delete them.