http://bugs.winehq.org/show_bug.cgi?id=28473
--- Comment #7 from Damjan Jovanovic damjan.jov@gmail.com 2011-11-20 04:22:08 CST --- There's no user32 calls in the trace when it freezes, but there is when it doesn't freeze. It seems the GUI thread exits for some reason? To prove this theory I'd need the "bt all" from the same running instance of uTorrent before and after the crash, then I could see which thread ID is the GUI thread.
Debugging why it actually exits could be difficult. A WINEDEBUG="+tid,+seh" trace might help, if the exit is caused by some internal error. Otherwise a debugger would have to be attached before the crash and some creative disassembly done.