Trouble with the Array Modifier when using an empty offset

I’m learning blender and am trying to create a spiral staircase using the array modifier and an empty. As soon as I attach the offset to the empty, my duplicate stairs grow in scale exponentially. I’ve been following the tutorial step for step, but getting different results. Here’s what it looks like:

http://cl.ly/330F2F1U3G1z0026100n

I’ve attached the blend below.

Thx.

Attachments

stairs.blend (366 KB)

Select the stair and in object mode press Ctrl+A / scale. If you press N to show the properties and look under Transform / Scale you can see the scale value for each axis is different. This problem comes up time and time again. The scale should be the same for each axis. Ctrl+A will reset it.
Next select the empty and change its scale value for each axis to 1. For some reason you changed it. To change the size of the empty you can do this in the Empty properties under display.
Scale is extremely important for any operations.

That help a lot, however it seems to rotate my steps at their center point rather than by the inside end (the end at the center). How do I reposition the center anchor point of an object?

Thx.