I still think you need to look to your addins. Try disabling all addins including COM addins and see if you get normal behaviour.
View, manage, and install add-ins in Office programs - Office Support
Office 2010 add-ins manager: how to enable, disable,add or remove add-ins?
You could also verify that there aren't macros in your Normal template which might be interfering with Save. Perhaps rename your Normal.dotm template (while Word is closed) and see if the problem persists.
Once you get to a point where the problem has resolved, you can add things back in one at a time to work out what is causing it.