Issue With New Flared Stairs

As you can see from the image, I am having difficulty placing the new flared stairs in my manor house - which would look absolutely amazing if only they would work.

The stairs I had there previously were identical but without the flare, and fit perfectly, even with objects at the top of the stairs. Trying to add any amount of flaring results in the "can't intersect with walls" error as above.

I have tried removing all the walls around the stairs (the only ones being those in front which they abut against), but this does not work. I can place them in the middle of the garden, where they do not touch anything, perfectly well, though those leading from the terrace at front and rear also cannot be altered without a "cannot intersect with fence" error. 

Removing walls/fences and then trying to place stairs afterwards does not work as they seem to ignore the moveobjects cheat and still will not place.

Anyone else have this problem, or a possible solution?

Also, removing one side of my stair rail causes the railing to no longer meet up on corners, which means I have to continue to put up with railings clipping through the walls.