why the number of queue of NIC impact the ping results?

broadcom bnx2x netxtreme2-5.2.50,kernel 2.6.27-19

@receiver:

insmod ./bnx2x.ko  multi_mode=1 num_queues=12/14/16

@sender:
ping receiver ->response OK


but no response when

insmod ./bnx2x.ko  multi_mode=1 num_queues=2/4/8/10

have any idea?

thanks
jon