Today I updated Twenty Eleven theme via the admin panel to v 1.3.
This has caused my child theme changes to add the sidebar to single post and pages to be shown incorrectly.
I have checked and the changes are still in place (in the child theme) but they are no longer working since the update.
The changes that were applied are detailed in this post:
Everything worked fine until today's update to 1.3 now single posts and pages have the sidebar but it is below the main content not to the side of it.
Thanks for any suggestions.