Generally we suppose that if there is any time lapse between event A and a subsequent event B, A cannot be the cause of B. But what if time were continuous, such that between any times t1 and t2, we might specify a distinct time t3? In that case, there would always be some time lapse between any two events: would that make causation as described impossible? Does conceiving of time as quantized solve the problem?
Alternatively, Bertrand Russell uses the problem you raise to critique the Humean account of causation and propose a successor. See Russell's discussion of laws of change in his book The Analysis of Mind .