RCM6750 - Ethernet flooding issue?

Just got back into some RCM6750 based work and am sorting out a little 
problem.  I noticed that when I had my board plugged into a hub, every 
now and then ethernet connectivity would go away.  Board was running 
other stuff, but nothing was making it out of the stack.  Diagnosing 
this now, and I isolated the device's ethernet connection to a PC, run a 
homemade icmp flood on it, and I can get it to do the same thing (not 
accept any telnet or http connections.)

I do have the current github code in my environment.  Anybody seen 
anything like this before?  Any troubleshooting tips for it?

Thanks.