Itunes 9 not remembering my AppleID password, got de-authorized

[alokeprasad]

Why isn't Itunes 9 remebering my AppleID password for purchases (even though I have checked the box asking it to do so)?

Today, when I synced my iPhone to my PC, iTunes 9 said that my PC was not authorized and I had to re-authorize it with my AppleID password. Why did that happen?

Thanks.
Aloke