MKMapview memory problem.Zooming-scrolling

I am developing a mapview application.When i look to instruments i see no leak in my application which is good.But my p开发者_开发问答roblem is whenever user scrolls,zooms in,zooms out the map,default mapview starts to allocate memories of MBs.When my application reaches about 25-30 mb then map releases some data which is about 5-6 mb s.But about 25mb of memory is still allocated.After a while my applications starts to throw memory warning.

The reason for it is that mapview stores the visited places in its memory and so in my application I want to know if there is a way to limit memory allocation of mapview or make it release some data before 25mb-30mb.

Thanks for your support.I would really be preciated.