Sidebar content and subsequent posts disappear

This has happened several times.

If I delete a category, or delete a page, all the content from my sidebars–links, categories, archive links, search box, etc–disappears from the index page along with all the subsequent posts that would be showing on the index page. THis is only for the index page as the content remains on the individual pages for subsequent posts.

The first time this happened, the only way I found around it was to create a completely new blog.

The same thing has happend with my using several completely different themes, so it’s not a problem with just one of them. And switching themes after it’s happened does not fix anything. Also, since I created new blogs several times, it’s not a bug with one in particular.

Hope someone has some feedback. Thanks, Ceara