I am running 6.3.2 on a non-smp x86 box with 2 network cards both RealTek 8139 chips each on a different subnet.

I have two processes each with multiple threads.  Process 1 uses the first network interface and process 2 uses the 
second network interface.  Both processes are reading and writing data over their respective interfaces fairly heavily. 
 

Running just one process (either one) io-net never consumes even 5% of cpu time.  Running both processes io-net consumes
 more and more over about 15 minutes until the system quits responding.  

Any thoughts?  Is this a problem with io-net or with the driver or ???  Next steps to debug the problem?

Thanx
Tim