http://bugs.winehq.org/show_bug.cgi?id=25657
--- Comment #4 from Andrew Nguyen arethusa26@gmail.com 2010-12-31 13:03:51 CST --- Judging from log output:
fixme:dpnet:IDirectPlay8PeerImpl_Initialize (0x142910)->((nil),0x4066d2,0): stub fixme:dpnet:IDirectPlay8PeerImpl_Close (0x142910)->(0): stub
The multiplayer functionality likely relies on DirectPlay, which is barely implemented in Wine. The native DirectPlay DLLs may be a suitable workaround.