Broken: all versions of blender
I just have been observing for the past month how my c:\ shrinking in size without any reason, it wen from 30 gb free space to 1 gb.
So I started searching what the issue is, and I found C:\Users\Denis\AppData\Roaming\Blender Foundation\Blender\ where all the majic happened, total size of the folder 40GB!
Inside all blender version folders that have been installed on my PC. From 2.64 to 2.76.
Starting from 2.71 cache folder is massive! I googled what it is, and some report it is when you activate cache bvh, I might have activated that feature in the past, but I definetly did not do that in 2.76 version, which I downloaded just to check if bug behavior is the same as in 2.75a. But that very folder already 5.31GB in size, inside bhv_****** files.
So I do not know if its a bug or something, but to let you know that it happenes. In Blender 2.76 I tested only class room blend from your web page, only once, and it already has 5.3GB of space occupied on c:\, I checked if class room blend has cache bhv enabled, and it does not actually.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps