Server 10.3.2 slow copying from server to Client machine

I am experimenting slow copying of files 10 minutes for a 28 Mb file from our server to a local machine. I've tried that at home with 10.3.2 Client and to took just seconds. Is there anybody in this forum that know about how to set an AsantÈ FAST Ethernet 690. I went in the System Preference and it was set to automatic. I set it manually with the mtu 1500 and full duplex. I haven't been able to test that since I am 70 km from the office. I remember in OS 9 once I've read about mtu problems and how to fix it, but I can't recall any of it. Before switching to 10.3.2 I never had any problems like this. Jacques PS The server is a G4 500 Mz and the client is an iMac 600 Mz both running 10.3.2 and we have a 10/100 Mbits hub.