Comment 5 for bug 99091

Retrace done:
...
#3 <signal handler called>
#4 0xb76fee1a in free () from /lib/tls/i686/cmov/libc.so.6
#5 0xb753e131 in IA__g_free (mem=0x83460b0) at gmem.c:187

#6 0xb71c2ec5 in gtk_xtbin_new (parent_window=0x8eace18, f=0x0) at gtk2xtbin.c:338
 user_data = <value optimized out>
#7 0xaf24ce81 in ns4xPluginInstance::SetWindow (this=0x9355508, window=0x96e3894) at ns4xPluginInstance.cpp:1195
 isXembed = 0
 win = (GdkWindow *) 0x8eace18
 user_data = (gpointer) 0x827fdb8
#8 0xaf267d6c in nsPluginNativeWindowGtk2::CallSetWindow (this=0x96e3890, aPluginInstance=@0xbf9b49ac)
    at nsPluginNativeWindowGtk2.cpp:139
 val = 0
#9 0xaf25bd98 in nsPluginHostImpl::InstantiateEmbeddedPlugin (this=0x8ce9ea8, aMimeType=<value optimized out>, aURL=0x92b0ce0,
    aOwner=0x8ea1700) at nsPluginHostImpl.cpp:3513
 inst = {<nsCOMPtr_base> = {mRawPtr = 0x9355508}, <No data fields>}
...

Tagging as mt-confirm for further processing