http://bugs.winehq.org/show_bug.cgi?id=23442
--- Comment #8 from Vitaliy Margolen vitaliy-bugzilla@kievinfo.com 2010-11-13 13:15:04 CST --- This problem has something to do with new plugin-container.exe process. For some reason it just dies.
As a workaround you can revert to old FF behavior for plugins (start them in the main process): Toggle following about:config entries: dom.ipc.plugins.enabled - true dom.ipc.plugins.enabled.npswf32.dll - false