Q: How do pages without security categories determine which wrapper to use?
A: They use the wrapper of the page you were on when you clicked the link to get where you are.

Q: What if I didn't get to the link from a wrapper? What if my buddy IM'ed or emailed it to me instead?
A: Then the use the general wrapper.

Q: What if I did get to them from a link on a page but for some reason the security category defaulted back to general?
A: Some script or image on the page you were just on is broken.

Q: Can I force the pagewrapper on these pages?
A: If you add the argument "pw_id=xxxx" to your link it will almost always force the pagewrapper, e.g.

Note:  If you click on the links here at the bottom before clicking on the ones at the top you will see the same pagewrapper because the bottom links will set the session on your browser.  Try them from top to bottom in a new browser to see the effects.