Problem Adding New Tabs.

I've installed Quick Tabs in a Drupal 7 website and cannot add new tabs to the block, the default two tabs are all that show up. There is a warning posted in the recent log messages whenever the add tab button is clicked, 'Undefined index: num_tabs in quicktabs_more_tabs_submit()', see attached file. The site consists of Drupal 7.22 with ctools 7.x-1.3 installed as a prerequisite for QT.