I have made a video for you:

Try out a shadow catcher method:
http://sketchucation.com/forums/viewtopic.php?f=322%26amp;t=54999
http://charlottesvillearchitecturalrendering.com/?p=494

I'm new to sketchup and Vray so not really sure but you can try reading this:

http://www.vray.com/vray_for_sketchup/manual/choosing_different_render_engines.shtml

It could be something with the iraddiance map settings

"When Min Rate and Max Rate are too low, "leaking light" happens even if the objects are joined together"..you will find where they talk about this somewhere in the middle

I fixed it!!!!

next to the 'reflection/refraction (background)' option, i've set the number to 1 (instead of 10).

Wow, 259MB!!! 😮 😮 While I admire your incredible attention to detail, you might consider figuring out how to make do with using a component for the rope vs groups. After all, unless the rope is glued to the beam, would it really follow every contour of the beam?

This is not meant as a criticism, your modeling skills are impressive to say the least, just a suggestion.

2015-05-06_070918.png

Your beam does not need to be so poly-heavy! You can achieve details like that in a render using a mix of normal/bump and displacement maps, with only enough geometry detail to define the silhouette. It doesn't matter so much for this model, maybe, but if you created an entire scene like this, I'd not be surprised if your computer gave up the ghost.