click play on an ogg, and watch rhythmbox explode.

$ gdb rhythmbox
GNU gdb Red Hat Linux (6.6-15.fc7rh)
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
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There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu"...
Using host libthread_db library "/lib64/libthread_db.so.1".
(gdb) run
Starting program: /usr/bin/rhythmbox 
[Thread debugging using libthread_db enabled]
[New Thread 46912496347088 (LWP 22040)]
[Detaching after fork from child process 22043. (Try `set detach-on-fork off'.)]
[New Thread 1084229968 (LWP 22044)]
[Thread 1084229968 (LWP 22044) exited]
[New Thread 1084229968 (LWP 22045)]
[Thread 1084229968 (LWP 22045) exited]

(rhythmbox:22040): Rhythmbox-WARNING **: Unable to start mDNS browsing: MDNS
service is not running

(rhythmbox:22040): Rhythmbox-WARNING **: Unable to notify network of music
sharing: The avahi MDNS service is not running
[New Thread 1084229968 (LWP 22046)]
[Thread 1084229968 (LWP 22046) exited]
[New Thread 1084229968 (LWP 22047)]
[Thread 1084229968 (LWP 22047) exited]
[New Thread 1084229968 (LWP 22049)]
[New Thread 1094719824 (LWP 22050)]
[Thread 1084229968 (LWP 22049) exited]
[New Thread 1084229968 (LWP 22051)]
[Thread 1084229968 (LWP 22051) exited]
[New Thread 1084229968 (LWP 22061)]
[New Thread 1105209680 (LWP 22062)]
[New Thread 1115699536 (LWP 22063)]
[New Thread 1126189392 (LWP 22064)]
[Thread 1126189392 (LWP 22064) exited]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1105209680 (LWP 22062)]
gst_base_sink_pad_getcaps (pad=0x12e3170) at gstbasesink.c:374
374       bclass = GST_BASE_SINK_GET_CLASS (bsink);
(gdb) bt
#0  gst_base_sink_pad_getcaps (pad=0x12e3170) at gstbasesink.c:374
#1  0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x12e3170) at gstpad.c:1967
#2  0x0000003a89a4c34f in gst_pad_get_caps (pad=0x12e3170) at gstpad.c:2051
#3  0x0000003a89a411a9 in gst_proxy_pad_do_getcaps (pad=0x1295890) at
gstghostpad.c:228
#4  0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x1295890) at gstpad.c:1967
#5  0x0000003a89a4c34f in gst_pad_get_caps (pad=0x1295890) at gstpad.c:2051
#6  0x0000003a89a411a9 in gst_proxy_pad_do_getcaps (pad=0x1295a40) at
gstghostpad.c:228
#7  0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x1295a40) at gstpad.c:1967
#8  0x0000003a89a4c34f in gst_pad_get_caps (pad=0x1295a40) at gstpad.c:2051
#9  0x0000003a89a411a9 in gst_proxy_pad_do_getcaps (pad=0x7d8c60) at
gstghostpad.c:228
#10 0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x7d8c60) at gstpad.c:1967
#11 0x0000003a89a4c34f in gst_pad_get_caps (pad=0x7d8c60) at gstpad.c:2051
#12 0x0000003a89a4dff9 in gst_pad_peer_get_caps (pad=0x12e3000) at gstpad.c:2086
#13 0x0000003a8a216fdb in gst_base_transform_getcaps (pad=0x12dee60) at
gstbasetransform.c:556
#14 0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x12dee60) at gstpad.c:1967
#15 0x0000003a89a4c34f in gst_pad_get_caps (pad=0x12dee60) at gstpad.c:2051
#16 0x0000003a89a4dff9 in gst_pad_peer_get_caps (pad=0x12decf0) at gstpad.c:2086
#17 0x0000003a8a216fdb in gst_base_transform_getcaps (pad=0x12deb80) at
gstbasetransform.c:556
#18 0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x12deb80) at gstpad.c:1967
#19 0x0000003a89a4c34f in gst_pad_get_caps (pad=0x12deb80) at gstpad.c:2051
#20 0x0000003a89a4dff9 in gst_pad_peer_get_caps (pad=0x12dea10) at gstpad.c:2086
#21 0x0000003a8a216fdb in gst_base_transform_getcaps (pad=0x12de8a0) at
gstbasetransform.c:556
#22 0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x12de8a0) at gstpad.c:1967
#23 0x0000003a89a4c34f in gst_pad_get_caps (pad=0x12de8a0) at gstpad.c:2051
#24 0x0000003a89a411a9 in gst_proxy_pad_do_getcaps (pad=0x12956e0) at
gstghostpad.c:228
#25 0x0000003a89a48f26 in gst_pad_get_caps_unlocked (pad=0x12956e0) at gstpad.c:1967
#26 0x0000003a89a4e343 in gst_pad_link (srcpad=0x13ed000, sinkpad=0x12956e0) at
gstpad.c:1638
#27 0x0000003a89a6c231 in pad_link_maybe_ghosting (src=0x13ed000,
sink=0x12956e0) at gstutils.c:1311
#28 0x0000003a89a6d7ac in gst_element_link_pads (src=0x12dc6f0,
srcpadname=0x2aaab959fb91 "src", dest=0x84aa80, destpadname=<value optimized
out>) at gstutils.c:1428
#29 0x00002aaab95951f5 in ?? () from /usr/lib64/gstreamer-0.10/libgstplaybin.so
#30 0x00002aaab9599d78 in ?? () from /usr/lib64/gstreamer-0.10/libgstplaybin.so
#31 0x0000003a8180af39 in g_closure_invoke () from /lib64/libgobject-2.0.so.0
#32 0x0000003a8181a838 in ?? () from /lib64/libgobject-2.0.so.0
#33 0x0000003a8181bc84 in g_signal_emit_valist () from /lib64/libgobject-2.0.so.0
#34 0x0000003a8181be53 in g_signal_emit () from /lib64/libgobject-2.0.so.0
#35 0x0000003a8180af39 in g_closure_invoke () from /lib64/libgobject-2.0.so.0
#36 0x0000003a8181a838 in ?? () from /lib64/libgobject-2.0.so.0
#37 0x0000003a8181bc84 in g_signal_emit_valist () from /lib64/libgobject-2.0.so.0
#38 0x0000003a8181be53 in g_signal_emit () from /lib64/libgobject-2.0.so.0
#39 0x00002aaaba609bee in ?? () from /usr/lib64/gstreamer-0.10/libgstogg.so
#40 0x00002aaaba60a668 in ?? () from /usr/lib64/gstreamer-0.10/libgstogg.so
#41 0x00002aaaba60e9a2 in ?? () from /usr/lib64/gstreamer-0.10/libgstogg.so
#42 0x0000003a89a6561d in gst_task_func (task=0x100b970, tclass=<value optimized
out>) at gsttask.c:192
#43 0x0000003a8144acf9 in ?? () from /lib64/libglib-2.0.so.0
#44 0x0000003a81449354 in ?? () from /lib64/libglib-2.0.so.0
#45 0x0000003e120062f7 in start_thread (arg=<value optimized out>) at
pthread_create.c:296
#46 0x0000003e110d0fbd in clone () from /lib64/libc.so.6
(gdb) 

100% reproducable, so further debugging possible if necessary.