When adding an existing module to a page all of the modules on the page move to the container selected for placing the existing module.  

Steps to reproduce.

1. Choose Add Existing module while editing a page.

2. select a module from another page.

3.  Drag the module to your container of choice.

4.  All modules on the page are then placed in the container selected.

This was also reported in 9.02 here https://dnntracker.atlassian.net/browse/DNN-9606

However, I do not have access to the page.  Any ideas?

Thanks for the reply.  Are there any other threads on this topic?  I've been using DNN for going on 10 years now and haven't experienced anything like this.  

I have a hunch that its related to the importing of content.  Pages that I create from scratch do not appear to have the issue.  Most of the pages experiencing the problem were imported from the theme sample content files.