Home page not getting sticky posts

Hello – I have a perplexing issue with the home page of a blog… https://beyondthedeal.net/blog”. The home page is set to show posts (not a static page). There are two posts set to stick to the home page. Recently the code started to get a post that is not set as a sticky and is pulling the wrong URL for the post. The result is a page not found error.

Home page looks for:
https://beyondthedeal.net/blog/2011/01/19/acquisition-trends-for-2011-and-why-groupon-rejected-googles-6-billion-acquisition-bid/

Actual URL of this post:
https://beyondthedeal.net/blog/2011/01/19/acquisition-trends-for-2011-and/

I tried to change the home page to show a static page (the About page), but is still tried to pull the post referenced above.

Here are my ideas for the possible cause, but I’m not sure.
– Theme compatibility issues with version of WordPress (the theme is Artemis and is two years old, the WordPress version is 3.2.1.).
– One of the plug ins is causing the problem.
– The php file ‘mainindex.php’ needs to be updated (I’m not a php coder, so I’m not sure).

Does anyone have ideas for the possible cause and solution? Thanks