I work for a school district that has a mixed environment of macs and PC's. We just recently deployed 160 iMacs with SL 10.6.4. We are behind a state managed firewall. Recently I was contacted by a network engineer from the state office telling me that we were flooding our connection with microsoft-ds traffic. Once I looked at the log I found that it was several of my new iMacs sending this traffic. Many had not even been logged into yet. They had just been imaged and were sitting there powered up. We forced a reboot on all iMacs and the traffic dropped to normal. After the macs sit for a day the traffic picks right back up and floods our network again. Some are being used and others just sitting there. Updating have been turned off. Any suggestions on how to solve is much appreciated.