Garbage collection working improperly?

[Oliver Walczak]

Dear List,
Trying the following hack:

>>> a = []
>>> for i in range(0,9999999):
		a.append(i)
>>> del(a)

Builds up a great list in memory and immediately deletes it. Unfortunately
the task manager shows me that i allocated about 155MB in memory before
del(), but del only releases about 40MB of them so i'm leaving about 117 MB
of reserved memory after deleting the list.
I'm using python 2.2.3 on WinXP.
Any ideas about that? How can i dealloc the left memory space?
Best regards
Oliver