I used to run into similar issues on the old Win XP machine I used to use for our SD4 printer - RH would completely freeze up forcing me to shut down the printer manually (I have mine plugged into a surge suppressor with an on/off switch) then close out RH and restart the computer.
the old computer only had 2 gig of ram - apparently just not enough (and that was the max that particular machine could handle - XP in general will only "see" 3.5 gig max, regardless of how much you stuff on the motherboard). I also could not run the filament visualizations on that computer - trying to do that would cause major issues, too.
All visualizations had to be turned off, and absolutely nothing else open or running in the background other than the bare essentials. Computer was disconnected from the internet so there would be nothing trying to update/download in the background that could possibly cause problems.
RH freezing up happened most often when trying to load & slice a larger file, or if I was trying out different slicer settings and re-slicing a couple of times.
I have not run into this problem since upgrading to a refurbished Win 7 computer with double the memory of the old XP machine (4 gig) - soon to be adding even more (adding another 8 gig for a total of 12, as well as upgrading the video card for better visualization performance)
I am not saying that this is definitely your problem, but it is something to think about if you are using an older computer.
for reference, I am using RH v1.0.6, with whatever version of slic3r that comes with it.
SD4 #1 & #2 - Lawsy carriages, E3D v6, Rumba controller board, mirror bed plate, X motor fan, upgraded PSU & Mica bed heater
SD4 #3 - in the works ~ Folgertech FT-5, rev 1
Printit Industries Beta Tester - Horizon H1