build crashes on devices with 512 ram or lower

hi.

i have succesfully ported an ios application to android using cocos2dx and marmalade.
i can run the application properly on devices having 1 gb or more ram but when i build that particular app on devices with 512 ram the game crashes.

can anybody let me know why is that happening?
and also please let me know how to use the single build for various devices.

How does it exactly crash? Do you have any error in log? Any stacktrace information? Did it run on Older iPads with less than 1Gb of RAM?