[Babul]

recursion could be that some of your functions are referring to eachother, like calling them selfes until a certain condition is met. this will fill up the heap/stack and crash when its full.
to get rod of that, organize your callbacks like "master" (the caller) and "slave" (the called), and then see if a slave (called) functin calls others, which again closes the circle. if that ever happens, its only about time when the script will fail.