I think what you are encountering is that if you Hide Guides, the Hide Guides command Locks them as well as hiding them. (You can observe this by looking at the View menu immediately after hiding the guides.)
This has been true of Illustrator ever since guides were first introduced, which I think was in Illustrator 3. It is by no means new to CS or CS2. But I don't see a good reason for it to act that way. So it might be a good feature request to ask that the Hide Guides command not lock them.