Slic3r sliding

I have created a 25.4mm x 25.4mm x 25.4mm cube in Rhino and exported as an .stl file. I loaded the cube into slic3r and generated a gcode file. When viewing the file in Repetier it looks as if each layer moves slightly in the x and y direction which creates an offset between the top and bottom of the cube.

Is this a slicer issue or a Rhino export issue?

Looking at the gcode in online viewers the offset does not appear, only in Repetier.

I have included the slic3r output.
Cube.gcode (196 KB)

Here’s a 1x1x1 cube stl file created in Solidworks.
Also included is the gcode created with Slic3r.

See how they work for you. Might point to where your problem lies.
cube.gcode (261 KB)
cube.STL (684 Bytes)