You have to run the util to update the folders.
One issue known in Win7-64 and possibly 32, is that windows, does not always refresh immediately, in fact it can take some time.
I have run this utility and someone looking at the same folder from another PC will sometimes see the updated icons well before I do, and I ran the util. Its not perfect, but it is better than nothing. And I believe windos is a limiting factor here.
If you use windows prior to vista look for a util called Folder Size. It adds an extra collumn in explorer shell with a reasonable figure for the size of files in the folder.
Ideally you need a Compliance Management system, but they don't come cheap