This may be unrelated, but something to think about is whether or not it becomes more frequent as you reboot or if it takes the same amount of time. If more frequent, then you might want to benchmark temperatures. Crashing or erratic behavior can occur if the CPU or Video Card/Chipsets are running too hot for example. It may very well be the bug, but if this was something that worked fine before and then started crashing, maybe looking at those temps will help you reach a more solid conclusion.

Good luck.