I had exactly the same problem. Completely hung my computer. Very, very aggravating. I was forced to Firefox due to that.
I'm using Win 7 64 bit and was using Java 33 & 64 runtime and also had the Chrome browser installed. I didn't know what was hanging my computer when using Opera Blink. It also happened when using Chrome. Removing components such as the Chrome browser and Java runtime and my extensions fixed it. I then put back Chrome, Java 32 bit and my extensions. That seems to indicate the problem was Java 64 runtime. Or maybe it was just a weird combination of programs that got in each other way.
Whatever. For me its now fixed.