I just ran into limit switch problems. One of the challenges I had was that the limit switch must be fastened ROCK SOLID. If it wiggles a tiny bit (<64th) and then triggers again the system stop the backing up and even starts to throw a limit switch exception into the mix to confuse one totally. All within the same micro second. Right now I only use Home switches and SoftLimits. I found a lot of noise from the stepper on the limit switch line, and that causes nuisance triggers for limits. Bad thing.... you come back from Lunch just to find out the machine stopped 2 minutes after you left, and went to lunch on it's own....
Lemo