http://bugs.winehq.org/show_bug.cgi?id=31994
--- Comment #32 from Erich Hoover ehoover@mines.edu 2012-10-23 12:29:51 CDT --- (In reply to comment #30)
(In reply to comment #27)
Created attachment 42242 [details] Windows-WireShark-NetworkMultiplayer-CreateGame
Thank you, this proves my tests are wrong and Erich's patch is correct. I'll dig deeper into this issue.
Did you try with an interface-specific broadcast? Maybe that's the only time this happens.