do the windows 7 machines have their own OU and GPO(s) associated to those windows 7 machines?
I assume you're using logon scripts per site or department as well, right?
Are your windows 7 boxes all under the same netlogon / startup.bat?
*you caught me at a bad time, I have a board meeting starting in less than 5 minutes, I'll have to check back in a couple hours.*