Wine maps that address to 127.0.0.1. Please, rerun with "WINEDEBUG=+winsock wine <app.exe> &> /tmp/output.txt" and paste the backtrace in pastebin.com. How to debug: http://wiki.winehq.org/FAQ#head-16da35b6327024d6ea576e3678488b16862d0f5e Source reference: http://source.winehq.org/source/dlls/ws2_32/socket.c#L2205
