We have an open ticket in the support system regarding network crashes that we are experiencing at a customer site. 

We have just upgraded to 6.41 in the hope that this would help, but it has failed to solve the problem (and has actually
 made it worse on one system). 

This is a standard x86 Quad Core PC system running current 6.4.1 with the e1000 driver and three NICs (two on IRQ7, one 
on IRQ11).

One thing that seems very curious is that after the crash, io-pkt has "lost" the IRQs that it had previously hooked. For
 example:

On a working system ("pidin irq" extract):

114707   1 sbin/io-pkt-v4-hc  
 114707   2 sbin/io-pkt-v4-hc  
		12                0    0 T-- @0x80b7334:0x812a060 
		13              0x7    0 T-- @0xb82225bb:0x81539c0 
		14              0xb    0 T-- @0xb82225bb:0x81c1180 
 114707   3 sbin/io-pkt-v4-hc  
 114707   4 sbin/io-pkt-v4-hc  
 114707   5 sbin/io-pkt-v4-hc  
 114707   6 sbin/io-pkt-v4-hc  
 114707   7 sbin/io-pkt-v4-hc  
 114707   8 sbin/io-pkt-v4-hc  

On the same system, after it has failed:

 114707   1 sbin/io-pkt-v4-hc  
 114707   2 sbin/io-pkt-v4-hc  
               11                0    0 T-- @0x80b7334:0x812a060 
 114707   3 sbin/io-pkt-v4-hc  
 114707   4 sbin/io-pkt-v4-hc  
 114707   5 sbin/io-pkt-v4-hc  
 114707   6 sbin/io-pkt-v4-hc  
 114707   7 sbin/io-pkt-v4-hc  
 114707   8 sbin/io-pkt-v4-hc  
 114707   9 sbin/io-pkt-v4-hc  

This seems very weird to me. How can io-pkt have un-hooked the IRQs? What does this mean? By the way, there is nothing 
in sloginfo.

I don't mean to circumvent the official support ticket (or imply that we're not getting a good response through that 
mechanism. We are.) But this seems very weird and I wanted to share it with a wider audience it case anyone else might 
have a useful comment/suggestion. And we are desperate since this is killing us in the field.

Any ideas/comments certainly welcomed.

Thanks,
Rob Rutherford
Ruzz TV