Sorry to necrothread this, but I'm having a very similar issue. I'm using version 3.63.06 and it doesn't matter if I log in as a user with restricted group viewing, or don't log in at all, I always see all of the cameras on the jpegpull.htm page.
We've never used groups before, but we have a need for it now and so I've started setting up groups, but I haven't found a way to restrict the view to only one group. Is this normally done through user accounts?
I may have a situation where a previous coder edited the htm files and removed the login requirement.
Edit: Never mind, we had an anonymous account with no password and that apparently breaks the groups / login functionality.