Hey micheus! Sorry dude, I'll compile a bit more information for you shortly and see if I can reproduce this from scratch. 
Oki doke, that wasn't hard at all. lol.
So, here are the steps -- v1.5.2
1. Make Cube
2. Pull one corner of verts on Z
3. Edge loop around the center
4. Bevel
See image for details.

Oki doke, that wasn't hard at all. lol.
So, here are the steps -- v1.5.2
1. Make Cube
2. Pull one corner of verts on Z
3. Edge loop around the center
4. Bevel
See image for details.