Assign a Word, Excel or PowerPoint to ALWAYS open in a preassigned Desktop?

I have Word, Excel and PowerPoint assigned to specific desktops but they do not always open in the pre-assigned desktop. If I open a Word, Excel and PowerPoint file from Mail, sometimes it opens in the desktop where I have Mail, some times in the pre-assigned desktop and I have not been able to find any pattern. I called Microsoft and totally uninstalled Office, reinstalled it and it did not solve the problem.

In Mission Control I have checked Show Dashboard as a Space, the other two (Automatically rearrange spaces based on most recent use and When switching to an applicacion, switch to a space with open windows for the application) are unchecked.

Does anyone else have this problem? Have you found a solution? If so, what is it?