When I try to set diagonals, I get an error "MyInstance is null. col 112".
I've found pathfinding script and just checked the area around 112 col.
Well it seems that myInstance isnt created, so I created it, but then there was no effect using set diagonals thing.
You can play with this
here some kind of "screenshots" (Cant send files from pc due firewall issues right now. also it shows 111 col, after my little research)
<img src="http://i.imgur.com/Mxq6kDz.jpg" border="0">
<img src="http://i.imgur.com/9846z09.jpg" border="0">
// sorry for my terrible English.