Hey TB
What method are you using for imaging? And more importantly for prepping the image prior to deployment?
Do you use sysprep? I used to use Ghost for imaging and Ghostwalk to create new SSID's for XP machines but had same problem as you. To get around this on the master image you remove the machine from any domain and disconnect from the network and follow this guide http://technet.microsoft.com/en-us/library/bb694095.aspx
With Windows 7 the new sysprep did this all for me, including generating a new sccm unique identifier, which can be tested by checking the smscfg.ini file and the unique ID is located in there.