ipq and nf_queue compatibility

[robert]

Hello,

I am porting a program that uses IPQ to NF_QUEUE, and the port went  
very smoothly, but I noticed that if I run the nfqueue version once,  
the ipq version stops working.  The NF_QUEUE version always works,  
but the other one simple stops functioning.  Is there a known  
incompatibility between the two?  Or perhaps is there some global  
state that I need to cleanup inside of the NFQUEUE version before I  
execute the IPQ version.  The kernel has both IPQ and NFQUEUE support.

This happens regardless of whether or not I call the function  
nfq_unbind_pf on exit.  Not really sure what that function does, but  
it was inside of nfqnl_test.c, so I tried it out.

any ideas?
--robert