SLES9 Network performance on p630 LPAR

I installed a SLES9 beta1 on a IBM p630 LPAR. When I copy a ISO file from another machine, the speed is very slow, only 10KB/S. The two machines are in a same 100M ethernet LAN. The low performance problem only occur with the SLES9 machines. Does someone have a good idea to improve network performance? -- USTC Alumni Email System