http://bugs.winehq.org/show_bug.cgi?id=31438
--- Comment #116 from Heiko lil_tux@web.de --- This bug is about the download problem not the install problem afaik.
Maybe I've made some progress. Since thinking about the pipe stuff I tried the qt 5.1.1 ipc-Example localfortune{client,server} which uses QLocalSocket and thus windows pipes. Guess what? Fast creating of fortunes results in "The following error occured: QWindowsPipeReader::completeAsyncRead: Unknown error 676". So it seems the problem isn't ws2_32 or WSAAsyncSelect, it's probably the QLocalSocket-communication over pipes between Origin.exe and OriginClient(Service).exe.
I'll test the example with qt 5.2 as well, to see if it's qt- or wine-related.