#12 Comment hiding broken across page navigation

[Laurence D. Owens, III]

To reproduce this bug:

- Visit a page of the Zope Book. For example:
http://zope.org/Documentation/Books/ZopeBook/2_6Edition/ZopeArchitecture.stx

- Turn off comments (press COM OFF button in BackTalk
toolbar).

- Go to the next page (press -> button in BackTalk
toolbar).

Comments will appear on the newly rendered page,
although the state of the "COM ON"/"COM OFF" button is
preserved.