http://bugs.winehq.org/show_bug.cgi?id=32074
--- Comment #10 from Rosanne DiMesio dimesio@earthlink.net 2013-08-03 11:59:52 CDT --- I can't confirm your theory about the number of files in a directory triggering this. I just tested in a directory with only 3 files in it, and the bug still occurred.
There may be something different about the encoding of the files where you didn't see this bug.