LuxRender: Orienting IES Lights

I have a simple scene setted up in blender with a simple light ( a plane ) with the following IES Profile:
http://www.erco.com/products/indoor/wall_mounted_l/floor_washl_173/images/eur_erco_floor_washl_sysove_76766.jpg.

However, no matter how I rotate the light on the local Z axis, it won’t change direction.

Here a screenshot of blender with the light selected rotated in both ways:
http://img534.imageshack.us/img534/5195/imgx.png
And here the render of the scene identic for both configuration:
http://img641.imageshack.us/img641/3527/img2k.png

Anyone knows how to achieve the rotation?

Thank you in advance!