I think the "initSocket -247" message is coming from slinger - do you have slinger running and do you try to restart it 
if it fails? Errno 247 is EAFNOSUPPORT. Unfortunately slinger does a number of operations in initSocket() so we cannot 
tell which has gone wrong. I suspect though that this is just a secondary affect of the problem within io-pkt itself 
caused by the driver.

We try to maintain forwards compatibility on the driver API and I don't recall any changes that would break a 6.4.1 
devnp driver from working on a 6.5.0 io-pkt. It may be that there was always an underlying problem in the driver and a 
change in the timing or similar may be causing the issue to get hit more frequently, this could also explain the 
variance with respect to io-pkt version and driver stripped or with symbols.

With io-pkt running at priority 21 by default, if it starts spinning on the CPU then the rest of the system can appear 
unresponsive. You can try lowering the thread priorities on io-pkt with -P for the main thread and -p tcpip rx_prio= for
 the receive threads, but note that the driver may register interrupt threads at any priority that is not affected by 
these parameters.

One area we have seen in a lot of drivers is that if callout_init() gets called again (e.g. from the driver's init 
function which gets called multiple times) after a callout has been started with callout_msec() then that can cause io-
pkt to spin. I would set up any callouts through callout_init() in the attach function and then leave it alone apart 
from scheduling with callout_msec() and stopping it with callout_stop().