The Program goes A->B, A->C, A->D etc
if your on B,C,D etc.
when you hit home, you come back to that activity.
but if you hit a popup notification (which is generated by a service) you always go back to A, and occational if you hit A->B Home, then click the icon again, your back a A
in both cases your actually A->B->A
so if you click C:
you are now A->B->A->C
which tries to generates a second service, and leads to confusion in the program since the secondary Views(b,c,d,ect) implements Runnable. and can spawn multiple threads instead of one thread per Activity.
so it's really like