If you access a network share on Windows desktops or server, your Mac leaves .DS_store files wherever you browse. These Mac OS X system files contain data about the directory and are hidden for Mac users. You can deactivate the Writing of .DS_store Files on Networks shares, so your Windows friends will stop complaining.
defaults write com.apple.desktopservices DSDontWriteNetworkStores TRUE
Reboot your Mac or Log out and back in again for the changes to take effect.
Reverting to Default
defaults delete com.apple.desktopservices DSDontWriteNetworkStores