Invisible wall that won't go away.

[Decorstudio]

I've recently upgraded from X1 to Home Designer Pro and I'm encountering a very strange issue. An invisible wall has appeared in my plan and is very stubborn, thwarting any attempt at removing it. Delete does not work.

It has really strange attributes, it duplicate when I drag it outside of the room, and moving/deleting it warps it back to where it originally appeared. The incredible strangeness of it all leads me to believe this is some sort of setting I've accidently turned on, or something.

I am on windows XP.