I have a custom power pc board with intel 82551 as the ethernet controller. The boot loader is uboot and the OS is Linux-2.6.24. The problem is that after the boot up, the ethernet controller stops responding after 90 minutes. It doesnt respond to ping. ifconfig shows the device, but if i try to down the device and then up it, it says "ioctl error". Then I have to reboot the system to get it right? Is it something to do with the configuration of the 82551? Please advice.