Question : Some DHCP clients not getting renewed, 1003 errors

We have a network of about 30 XP clients running unders Windows SBS 2003 Premium.  In the past week, we have been having problems with some clients not getting renewed.  It's been happening once every day or two--when a user logs on in the morning, their LAN connection shows limited/no connectivity.  Repair/Renew doesn't work; I have to manually put in an available IP address, gateway, etc., and then they are picked up right away.   I have restarted the server several times, updated NIC drivers (Intel Pro 1000 EB), ran the CEICW.  Everything looks ok in the DHCP server (yes, the server handles DHCP).  I also checked our switch, and Spanning Tree is not enabled.  The problem clients are spread out around the building.  Does anyone have any ideas?  I thought maybe the next step would be to delete and reenter the scope?

Answer : Some DHCP clients not getting renewed, 1003 errors

What firewall are you using: Some firewalls block DHCP broadcasts without being administratively allowed as an exception.

Here is an example:
http://www.experts-exchange.com/Microsoft/Windows_Security/Q_22801936.html?sfQueryTermInfo=1+chiefit+dhcp+isa+rule

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Rogue DHCP servers can cause microsoft DHCP servers to shut down. Download DHCPloc.exe and run that utility. That will point out any rogue DHCP servers. I know that rogue servers has already been discussed, but DHCPloc.exe is free and the best utility for tracking down rogue servers. DHCPloc.exe wasn't mentioned.
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Furthermore, look in your DHCP logs. If you are getting Discovery request, but NACK instead of offers, then that will help narrow the problem.

HOW TO, you ask:
http://support.microsoft.com/kb/298367