Help! Why can't I stack?

[Xlegs]

This really bugs me. I own a hotel and whatever i do i can only stack 2 things at a time and thats it. I'm trying to make my rooms look so cool and for some reason i can't stack. my stacking skilsl are awesome but i just can't stack and i'm the owner. and btw the hotels oldschool v18.

I know this can't do much but if you want the URL or a photo of/to the hotel just pm me.