Contacts Memory Allocation

Hi I am making an application that involves editing the fields inside a contact Item.

During the process of testing that application, I found out that each time you edit a contact, 1kB approx is added to the memory allocation of the contact.  For example, I add a ringtone to the contact, it moves from 8kb to 9kb. Then surprisingly, if I delete the ringtone, it moves from 9kb to 10kb. Hence, by doing this to all the contacts, the memory of the phone overloads because i am adding 500kb for each run and i have no way of recovering the memory eaten up

Is this really the case? Or is my phone mem not functioning well?

This is true even if i edit the contacts using the default phone contacts application. 

Any thoughts or comments are welcome.

I hope someone will help me verify this. Btw, I am using a nokia 6600.