Server won't render due to "3gig switch"? Help!!

Hi all, thanks for any help. Frustrating issue here.

Basically, we have 14 Shuttle computers running renders for 3DS Max scenes, via Vray and Backburner. Recently we built a new custom computer, which has worked great except it refuses to accept the connect from other computers.

Eventually, it seems to come down to, SOMEHOW, the 3-gig switch we have in the boot.ini. When it is turned down to 2.9, suddenly the machine will accept the incoming render task, any higher and zero work. We had a similar issue a while back with a custom machine that would only take 2.8.

Has anyone experienced this before, or know anything about the issue?? It's simply ridiculous, as far as I can tell, and it's really going to cause a lot of issues in the future if all custom machines will need to be "tweaked" to see how much of the 3 gig switch it can handle.

Hope I have this posted in the right section, it's fairly vague... thanks all!!