Problem with auto save of draft

I am using Catch Kathmandu Version: 3.5.1, with Wordpress 4.3.1. The theme locks up when auto saving a draft of any changes made in the post. After researching the problem through elimination of plug-ins, it became obvious that s2Member, Version 150925 was the problem. I can eliminate the problem by simply switching to another theme without any other changes and all are compatible with s2Member. It does not happen with other themes, just Catch Kathmandu. This has been ongoing with previous versions of Catch Kathmandu. If a change is made to the post, the auto save draft feature kicks in and displays the following message... Saving Draft... Last edited by * on * The save locks up and I cannot save the changes, publish or any other forms as they are greyed out. My only recourse is to copy the text with the changes, exit the post, reopen the post and quickly replace the text and then click on save draft. If any changes are made after this - the auto save feature again locks up. I would really like to use s2Member. Is there a recourse? Thanks