You can't really say which games are "sensitive" to overclocking.. all games are susceptible to crashes if the system is not stable..
I have both games you have, and I can run then flawlessly for hours. They are both fairly CPU intensive games, and would stress your system quite heavily.
It seems obvious that your overclock has not been fully tested, and you should run prime95 or do some video encoding for at least 6 hrs or more (24hrs is my gold standard), and see if crashes or errors occur. If it does, then it's time to see which part of your o/c failed (CPU? RAM? M/B?) and lower your o/c as needed.
Oh, FYI my 1700+ is at 2.4v (200 x 12) while running SETI@home 24/7, temps are constantly ~50 deg C