I have a similar interesting one.
I have a 100Mb router with four PCs plugged into it.
The router has a green light to indicate 100Mb service which goes orange to indicate 10Mbs.
One of the computers always gets an orange light, even though I have changed the NIC, the cables and the router port.
I don't really care, because it is only networked to get ADSL, but it still seems very odd.