The 100mbps thing is a possibility. Also could be that you need a different cable (i.e., crossover vs non crossover). Sometimes the routers I've seen have special needs in that area. Does your router have a TX/RX switch next to the port?

Please see ethernet troubleshooting steps here.

Make sure that you can plug a PC computer into that port and that the PC can work on the network when plugged into the port. Don't use the empeg as a network troubleshooting device, make sure the network is functioning FIRST, then plug the empeg into the network.