I have never encountered this error, but I would imagine it is because of the application hooks that DisplayFusion uses. You can try disabling the hooks on the Troubleshooting tab in the DisplayFusion Settings window, but some features will no longer work properly: http://www.binaryfortress.com/displayfusion/help/#settings-troubleshooting
The last item on the page will explain what disabling the hooks will do. I would be interested to hear if this does correct the problem. Thanks!
