#0  0xb7bf53c2 in g_type_check_instance_cast ()
   from /usr/lib/libgobject-2.0.so.0
#1  0x0805041f in ?? ()
#2  0xffffffff in ?? ()
#3  0x080886d8 in ?? ()
#4  0x0804f4c0 in ?? ()
#5  0x083884f0 in ?? ()
#6  0x00000000 in ?? ()