Hi Pavel,
Is there a chance to find, what's fatal for the logon process, eventually to make a quick-and-dirty fix?
No. Sometimes the fixme doesn't even say what's wrong. It can be a hint, that's all. I see lots of shdocvw messages, so I'd try overriding that first.
There was also this one:
fixme:winsock:WSAIoctl SIO_GET_EXTENSION_FUNCTION_POINTER {25a207b9-ddf3-4660-8ee9-76e58c74063e}: stub
and that was mentioned in bug 14873. http://bugs.winehq.org/show_bug.cgi?id=14873
The missing SIO_GET_EXTENSION_FUNCTION_POINTER support is a longstanding bug in Wine. Someone was just asking about it here last month: http://www.winehq.org/pipermail/wine-devel/2009-September/078408.html
The patches mentioned address AcceptEx, whereas the GUID above is ConnectEx. ConnectEx doesn't seem too hard, and it doesn't appear as though it needs server support, so you might be able to hack something together for it to see if that's what's causing it. --Juan