http://bugs.winehq.org/show_bug.cgi?id=34367
--- Comment #33 from Ken Thomases ken@codeweavers.com 2013-09-15 16:21:28 CDT --- All of the complaints about things being "lost" are about leaks. Those aren't good, but probably not the source of the freeze. The stack traces on those indicate where the leaked block was allocated, so of course RtlAllocateHeap() is often on the top of the stack. But in most of those cases, if not all, the rest of the trace goes into the game program itself, so it's indicating game bugs.
Of more interest are the invalid reads and the use of uninitialized values. Most of the ones that were reported seem to be inside the game code, too. Valgrind stopped reporting after hitting its limit, though.
You could try to disable or suppress certain checks to try to reduce the noise, but I'm not sure how fruitful it's going to be. There are so many problems that finding the one actually causing the freeze is going to be hard.