For the issue you are having for renaming or adding divs, i have uploaded a shared.js file which will need to replace your current shared.js file that is located under your Dreamweaver Configuration Folder / Shared/WebAssist / CSSSculpotor
Make sure to have DW closed and delete the cahce file before restarting. This issue seems to happen every once in a while but it is difficult to debug since it is not easy to reproduce. and like you said it is hard to reproduce constantly.
Let me know if the update fix your issue.