This is a documented bug: http://bugs.winehq.org/show_bug.cgi?id=23123. You can either contribute to solving the issue or try some of the workarounds discussed in the bug report. If you discover something that might be helpful for other users, document it in the World of Warcraft AppDB entry http://appdb.winehq.org/objectManager.php?sClass=application&iId=1922.
