Postname Not Showing for Some Posts

Some of my post names are not showing properly when I preview. I have my permalinks in my setting set to /sample-post/ (aka /%postname%/)

My other posts show up fine. However, ever since I installed Simple Paginated Posts plugin (http://wpplugins.tlamedia.dk/simple-paginated-posts/), my permalinks do not show up properly in the URL. I read that if I install All In One SEO Pack plugin that it would fix it. It did not. In fact, I even tried to custom change the Title Field and it didn’t work. I also read that changing the .htaccess to 666 from 644 would also fix it. it did not.

I deactivated the two plugins and it did not fix it. Lastly, I read up on http://codex.wordpress.org/Using_Permalinks to see if I was missing anything. I’m out of ideas and am getting to a dead end. Please help.