Mogaraghu:
( While I wonder how it ever worked earlier since the displayHome() was the first function in the loop)
The answer to that is that memory overruns are unpredictable. When you write to some part of memory you are not supposed to, the result depends on what that memory is actually being used for. Sometimes it's relatively harmless (in the short term), sometimes it isn't. As you code changes, the things stored in that memory location change, and where you overwrite changes, so suddenly, it crashes, but it has nothing to do directly with the lines of code you changed. Invisible and painful.