Hello Shub,
I have done a wireshark captures on a simple nmap using one port (succeeded) and on
a sequence of ports (failed).
It looks like there may be a problem with multiple threads/sockets. The problem
happens when an open port is found. The SYN-ACK packet never gets sent back and
consequently the side that started the SYN never sends an RST packet.
The link sent by ActoryOu provided a way to prevent the problem.
thanks,
-dwd