My original post explained everything I had to keep repeating.
Sorry, but it didn't. If you had just said that you reinstalled Twenty Ten instead of "I have reinstalled my theme," it would have saved us a lot of trouble.
I did change my header on Oct 1, but I have the same theme. I have changed headers before with no problems. Could that cause a problem?
Anything's possible, but I'm going to say that's unrelated.
The reason why we suggest deactivating all plugins and switching to the Default or Twenty Ten theme is because plugin and theme-specific issues are easy to fix. Would you rather have your mechanic disassemble your entire car and then find out that you just need an oil change?
Since you're currently using Twenty Ten, we need to approach the theme question a different way. Go to the Appearance section of your admin panel, select the "Install Themes" tab, search for "Coraline" and install and activate it. Then, let us know if the posts appear. If they don't, deactivate all of your plugins and check again.
I know this frustrating, but it's important to know if this is a minor theme-related issue or a major issue.
I apologize if you've already done this, but it's just not clear given this topic's current state.