Vlado,
I am having a similar crash with VRayRT in max 2013 with the latest build.
RT loads all the bitmaps then crashes when it starts to calculate the lights. If I run RT a second time it all works perfectly.
GTX560 with the 301.42 drivers.
If you want a scene I can pack it up and send it over to you or I can just send a screen grab of the console.