i haven't experimented all that much with paper size.
there is no reason it shouldnt be easy to configure it to work with that size paper and cards. the first question is, does changing the top margin settings have an effect on the printout. check the units of measurement in the paper configuration options and make sure you've selected A4 of course.
if the settings have no effect, then either there is a programming bug or you are changing the wrong settings. i am away from my main computer until the 28th so i can't experiment and fix until then, but if you give me a report here or by email i will check into it then.