Any Samba Ninjas?

I have a samba server on the network with about 10 machines. Some of the directories and files are shared between multiple users. After getting the groups set up and everyone into the right group everything seemed to be working smoothly. Users could connect to the directories they were in the right groups for and open, save, edit files etc. I have however run into a problem.That problem is with Microsoft Office files and the use of a temp file as an intermediary between the origional document and newly saved document.

I assume that Linux/Samba treats the saved document as a new file and puts the user that modified it as the owner and group as well as modifying the permissions. How can I get around this?

Thanks