http://bugs.winehq.org/show_bug.cgi?id=20467
--- Comment #19 from Henri Verbeet hverbeet@gmail.com 2011-07-03 02:07:11 CDT --- (In reply to comment #18)
Sadly this one is still there as you can see from the attached back trace (I've added a new one since you said lots of things have change, maybe the source of the bug becomes clearer from this log).
I'm afraid comment 17 was a bit bit on the optimistic side. Actual refcount separation was done until commit e5d69ba9237de0d461c5896d4377606c23700c9d (notice the date on that). Could you give this a try with current git, and create a new log if the crash still happens?