I have submitted a one line patch to add a timeout value to pcap_open_live() in packet.cpp.
This ensures compatibility with FreeBSD kernels >4.2-RELEASE, and should improve performance under packet intensive circumstances for newer FreeBSD and Linux kernels.
Systems that do not support timeouts will ignore this value.
The disadvantage to a zero timeout is that packets are read from kernel to user space as they arrive. This is expensive.
The patch sets the timeout to 100ms, and should be quite sufficient for ShowEQ purposes.