http://bugs.winehq.org/show_bug.cgi?id=31438
--- Comment #7 from Per Johansson per@morth.org 2012-08-16 10:09:43 CDT --- The thread writing the files is blocking in this call for a long time:
003b:Call user32.MsgWaitForMultipleObjectsEx(00000000,0609d8a0,ffffffff,000004ff,00000006) ret=67155933 ... 003b:Ret user32.MsgWaitForMultipleObjectsEx() retval=00000000 ret=67155933
Presumably it's waiting for input. That's all I know for now (don't think I'll look more at this for a while)