Hi guys, thank you!
Yes, the picture is leaning to the wall on the far corner, but i see it's not so noticeable 
I personally don't mind too much to wait a little more, at the moment: perhaps i've never been in such a hurry to compel me to wish for 30mins renders, THANK GOD! BTW, a couple of times I happened to be in a little hurry, but i simply ran Indigo in cooperative mode through the LAN of my office, and it all went just fine: rendertimes were still huge, but consistently shorter than a one-pc process..
I'm not a fan of long rendering times, to tell the truth to you guys: it's just that Indigo integrates itself so well into my SketchUp workflow, that now I fell a little uncomfortable working with other systems: I think it's a sort of cursed addiction 






). Gonna try pilou solution: thanks mate!
THANKS! 
i've been forced to create a layer to contain all the windows of this kind, and then freeze it when not working on...