eth0 link negotiation and link delay with CentOS

Hi,

  We have some Dell PowerEdge T300 running CentOS 5.3 and we are seeing speed negotiation problems (non-optimal speed) and link delay of up to 10s on NIC-1 (eth0) on those systems. We have upgraded to the latest BIOS without any change. 

  The network will negotiate to 10Mbps FD when connected to a 100Mbps capable switch and to 100Mbps FD when connected to a 1Gbps capable switch.

  Any hints appreciated.