I have an x86 board with two 10/100/1000 ports using RealTek 8169 chipsets.  I'm using a driver for the RealTek 8111 
family.

Everything seems to work fine until...

I have the two ports on different subnets and I put the system under heavy load.

A common problem is that the second port will lose its IP address.  I set it again using ifconfig.  After a short period
 of time under load the ports stop transmitting.  Both ports stop.

Both ports show that they are up and still have their IP Address.  The only thing interesting is that ifconfig flags 
returns OACTIVE after they are hung.  This flag does not appear when they are working.  I have to reboot to get things 
working again (I could probably unload and reload the drivers, just haven't bothered yet.)

Anyone seen this problem before?  Does it sound like a problem with the driver or ???

I'm looking for suggestions on how to proceed.

Thanx
Tim