I've owned several of these PCBs over the years and only encountered the freeze bug once or twice, which occurs at the end of Stage 6. To put it in perspective, about 99% of the the time I would get through Stage 6 without it freezing. Apparently it can also freeze on the last boss, though I've never experienced it.
So I wouldn't worry about it. It's also now possible to "upgrade" from this MASTER VER to the bug-fixed one, without soldering.