I do not have it without the plugin anymore.
I can give you the steps.
1. Create a standard Site Sculptor site.
2. Add a static plugin to a page.
3. Now if you select/deselect the us plugin page title.
4. Check you will see if you end up with the option deselected you will find the TITLE tag has been emptied obviosuly the Plugin does not remeber the previous Title so it leaves it blank.
To be honest I do not think this is really a bug just a downside of changing your mind if you want the itle from the plugin or not.
One sort of idea could be that the plugin does not remove the original title in future but comments it out then returns it if deselected later on.
I hope that explains the issue. Like I said not really a bug but a trade off at the moment.