Switches say they do 10/100/1000, but they forget to mention that the switch most likely requires autonegotiation, which was a feature that was added much later than when most of these compact mac ethernet adapaters were made. The switch sends an autonegotiation request to the Mac, the Mac says "Duh" and doesn't respond, The switch tries a few more times, Mac still says "Duh", and the switch decides since the device didn't respond to autonegotiation it is obviously broken, not working correctly, or not compatible, and just ignores the Mac, all the while the Mac is thinking "When are we going to establish a link here?"

The only way around this is to get a switch that either allows for physical setting of the mode via a hardware switch (so, a pre-autonegotiation switch that required manual mode setting) [Note: Some modern switches will allow you to set the mode in software. 99% of the time this still will not work] or an old 10BaseT switch that only does 10BaseT so here is no need any any negotiation since the it only does one speed.