Python memory deallocate

[mardif]

In python 2.5 this was resolved, ok, but i can't use any python version
then 2.3.5.
This project was initializated with this version, and now it can be
dangerous change version, even because I use McMillan installer for
compile e build an executable.

So, my initial window is a "menu window", when i can choose, for
example, upload foto for print, or create an object as PhotoAlbum.

If i'will choose PhotoAlbum, it will allocate 200Mb. well!  if i decide
to abort this work, i will return to initial window. and if i will
click in PhotoAlbum ago, the memory will increase to 350-400Mb.

It's that!!! I don't understand why!!! when i abort the work the first
time, i call

app.Destroy()
del app

Why Python ( or GarbageCollector, or.... ) don't deallocate memory??
If it's not possibile, why python don't reuse the memory "cached"?

thx a lot