Dear All: This is Haiwei from Singapore Panasonic Laboratories Pte Ltd. I just tested -daemon-mode using udp-sender.exe (window version) under winXP. Below is the command used and its corresponding results: [command] udp-sender -M 239.1.1.1 -P 5004 --daemon-mode --nokbd --autostart 1 -f test.txt [results] Udp-sender 2007-02-18 Using mcast address 234.81.112.185 UDP sender for test.txt at 10.81.112.185 on Intel(R) PRO/100 VE Network Connecti on - Packet Scheduler Miniport (00-00-e2-5b-c7-66) Broadcasting control to 239.1.1.1 Starting transfer: 00000009 Transfer complete. bind socket to 10.81.112.185:5005 (Bad file descriptor) [my comments] There is no need to call bind() again when transferring is terminated. Next receiver should share the same IP:Port as 10.81.112.185:5004? I have tested udp-sender (2006.9 version) under Linux (Fedora 5.0), it works well. So I doubt that udp-sender.exe (window version) may need to be updated. Your comments are welcome. Thanks in advance. Best Regards, Mr. Haiwei Sun R&D Engineer Panasonic Singapore Laboratories Pte Ltd Singapore