connection light on switch flickers constantly

I recently upgraded my home network switch from a 10MB switch (Farallon
Starlet/4) to a 10/100MB switch (D-link DSS-5+). All my connections seem to
work OK, but with one of my PC's (an eMachine with a 3 COM Fast Ethernet
3C905B-TX card), the green connection light on the switch is not a steady
green, like the rest. Instead it flickers constantly and very fast
(6-8/flashes per sec.). It does this no matter which port on the switch I
plug it into and does it even though there's no network activity. I didn't
(and still don't) have this problem on my older 10MB switch. And although
the connection seems good between this PC and all the rest,(all PC's can see
each other and transfer speeds seem similar), the flashing light is kind of
irritating. Any ideas what's causing the connection light to flicker?

Thanks -- Gil Theissen