SBS 2003 No Internet

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I just installed SBS 2003 on my clients server. After
running the set up on the workstations I have run in to a
very weird problem. There are a total of 15 systems. Of
the 15 systems, only 7 of them are able to connect to the
Internet. I could see if none of them connected, but why
would some connect and not the others?