My problem is now solved with the theme being updated.
I have changed templates and it seems that it will work with twenty eleven however when changed back it does not work again.
So this means it has been narrowed down to the theme template Directorypress Responsive Theme.
Anyone with ideas out there?
I too are having the same problem.
I have deactivated all plugins with same result.
I have also changed the permalinks and saved and then changed back to post name and saved.
I have also used the repair tools and also clicked on one at a time.
Nothing has changed.
Something is going on here and it seems more and more people are experiencing this problem.
Can anyone help here?
