is it a bug in Module copy or i am wrong??

[yoma]

python version 2.5 in module copy

we all know that copy have two method: copy() and deepcopy().
and the explain is
- A shallow copy constructs a new compound object and then (to the
  extent possible) inserts *the same objects* into it that the
  original contains.

- A deep copy constructs a new compound object and then, recursively,
  inserts *copies* into it of the objects found in the original.

so i try a example:
import copy

class A:
    i = 1

class B:
    a = A()


b = B()

x=copy.copy(b)

y=copy.deepcopy(b)

print id(x.a), id(b.a)

print id(y.a), id(y.a)

the result:
14505264 14505264
14505264 14505264

So maybe i have a wrong understand to deep copy and shallow copy or
it is  a bug ?

please help me!!