I haven't tried to force two categories all the time, one in one region of the page and one in another.

The best way might be via a plugin that restricts posts to a certain category. Then, it wouldn't matter what the user selects outside those two lists of posts, and it wouldn't matter what categories showed up in the url. ("It wouldn't matter" in the sense that the two category lists wouldn't be affected).

My site doesn't do exactly what you want, but you can take a look at it for ideas. It's at

www.thewildlifeporch.com

You may want to consider the following:

The sidebar at the right of my blog contains several instances of a plugin. The plugin shows categories and posts from the linkblog, but only the categories you tell it.

For instance, the first instance of the plugin has been set to show only "Affiliates" and "Featured Products" and their post titles.

The second instance of the plugin has been set to show the "About" category without the name of the category, just the post titles.

The third instance is set to show only "Credits" and the post titles

You can use the exact same widget, give it the id of the blog you want to pull from, and the category you want, and it could do something similar.

You won't get the post contents, though, unless you modify the widget.
Where is the widget you ask?

It's a plugin/widget I wrote but haven't cleaned up and uploaded to b2e yet.

If you decide to go this route, let me know.

Cindy Rae