I suspect that the homepage is in fact a static homepage on which you selected the correct secondary menu to use. Unfortunately, categories, search results and some other page/post types are dynamic, so you cannot select a particular secondary menu. Noting that secondary menus must be selected manually to apply to the particular page or post, there's no way to do it either broadly or dynamically.
When you get down to something like http://www.therealli...ctober-11-2011/
in the editing mode, you will find a selection drop down to choose the secondary nav to apply to that particular post. But the category pages aren't "edited" as such.
Now there's a way to do it. You won't like it because it's not easy.
1. You need to create and name a secondary nav menu for each category. There are no child or grandchild options for secondary nav, as a side note.
2. You need to create a page (not a post) for each specific category or subcategory you have. Use any template you desire from the list.
3. Download a plugin called TPG Get Posts from http://www.wordpress...extend/plugins.
Activate it and use the instructions found via that link to include posts from the applicable category on the matching page. Save.
4. Style the post listings on your page as you wish. I know that thumbnails are possible, but generally TPG doesn't provide them in their default shortcodes. You have to do some serious research and editing.
5. Go back to your page and make any content or style changes you wish. In edit mode, select the secondary nav you created. Save your page.
6. In your main menu, replace the category link you have with its corresponding page (just finished saving). View your homepage... navigate to the menu link you just created and voila, there's your secondary nav.
Unfortunately, it still won't work for search results. You'll also have to manually add the secondary nav for that category to all posts in the category. No way to do it globally - a WP