According to Apple (
http://docs.info.apple.com/article.html?artnum=301711 ) :
Mac OS X 10.4: How to prevent .DS_Store file creation over network connections
This article contains advanced material intended only for those who are looking for information on .DS_Store files. If you do not already have an opinion on this matter, you can disregard this article.
To configure a Mac OS X user account so that .DS_Store files are not created when interacting with a remote file server using the Finder, follow the steps below.
Note: This will affect the user's interactions with SMB/CIFS, AFP, NFS, and WebDAV servers.
1. Open the Terminal.
2. Type:
defaults write com.apple.desktopservices DSDontWriteNetworkStores true
3. Press Return.
4. Restart the computer.
If you want to prevent .DS_Store file creation for other users on the same computer, log in to each user account and perform the steps above—or distribute a copy of your newly modified com.apple.desktopservices.plist file to the ~/Library/Preferences folder of other target users.
These steps do not prevent the Finder from creating .DS_Store files on the local volume. These steps do not prevent previously existing .DS_Store files from being copied to the remote file server. Please note that disabling the creation of .DS_Store files on remote file servers can cause unexpected behavior in the Finder (click here for an example).