Do you, by chance, reset Safari often? I've noticed that after resetting Safari, iTunes will always ask for a password once and sometimes twice.
It's to log into the iTunes store. I think it asks once for iTunes and once for apps.This is doing my head in!! Every time I open iTunes I have to put in my password and apple ID, sometimes twice!! Is there a fix? I have seen a couple of things online but none of them seem to be working.