The crash in rhythmbox when connecting to mms streams through libmms is an old one. It usually happens when switching to a mms:// source from listening to something else (e.g. an mp3 file). I've seen exactly the same behaviour in every release over the last 3-4 years. Switching from listening to a mp3 file to a mms:// source will cause a crash almost every time. I'm not sure if the problem lies in inappropriate data initialisation by rhythmbox, or a bug in libmms.  A BT from the crashing thread shows:


Thread 30 (Thread 0xa91feb70 (LWP 24118)):
#0  0xb0ec7dcd in ?? () from /usr/lib/libmms.so.0
#1  0xb0ec93bd in mms_connect () from /usr/lib/libmms.so.0
#2  0xb0ecbec1 in mmsx_connect () from /usr/lib/libmms.so.0
#3  0xb0efcc07 in ?? () from /usr/lib/gstreamer-0.10/libgstmms.so
#4  0xb76bedb8 in gst_base_src_start (basesrc=0xaf1435c8) at gstbasesrc.c:2649
#5  0xb76c4f27 in gst_base_src_activate_push (pad=0x904f0d0, active=1) at gstbasesrc.c:2874
#6  0xb763a00f in gst_pad_activate_push (pad=0x904f0d0, active=1) at gstpad.c:923
#7  0xb763a9f5 in gst_pad_activate_default (pad=0x904f0d0) at gstpad.c:590
#8  0xb763aafc in gst_pad_set_active (pad=0x904f0d0, active=1) at gstpad.c:679
#9  0xb761915b in activate_pads (pad=0x904f0d0, ret=0xa91fdc5c, active=0xa91fdcbc) at gstelement.c:2632
#10 0xb762b9f7 in gst_iterator_fold (it=0xaf12a380, func=0xb7619130 <activate_pads>, ret=0xa91fdc5c, user_data=0xa91fdcbc) at gstiterator.c:545
#11 0xb761908f in iterator_activate_fold_with_resync (iter=0xaf12a380, func=<value optimised out>, user_data=0xa91fdcbc) at gstelement.c:2664
#12 0xb761b69b in gst_element_pads_activate (element=0x90e2000, active=1) at gstelement.c:2701
#13 0xb761dbfb in gst_element_change_state_func (element=0x90e2000, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstelement.c:2778
#14 0xb76c61dc in gst_base_src_change_state (element=0x90e2000, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstbasesrc.c:3017
#15 0xb761a435 in gst_element_change_state (element=0x90e2000, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstelement.c:2548
#16 0xb761d928 in gst_element_set_state_func (element=0x90e2000, state=GST_STATE_PAUSED) at gstelement.c:2504
#17 0xb76197f0 in gst_element_set_state (element=0x90e2000, state=GST_STATE_PAUSED) at gstelement.c:2405
#18 0xb7609827 in gst_bin_element_set_state (element=0x9050b50, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstbin.c:2118
#19 gst_bin_change_state_func (element=0x9050b50, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstbin.c:2417
#20 0xb761a435 in gst_element_change_state (element=0x9050b50, transition=GST_STATE_CHANGE_READY_TO_PAUSED) at gstelement.c:2548
#21 0xb761a22e in gst_element_continue_state (element=0x9050b50, ret=GST_STATE_CHANGE_SUCCESS) at gstelement.c:2222
#22 0xb761a4bf in gst_element_change_state (element=0x9050b50, transition=GST_STATE_CHANGE_NULL_TO_READY) at gstelement.c:2585
#23 0xb761d928 in gst_element_set_state_func (element=0x9050b50, state=GST_STATE_PAUSED) at gstelement.c:2504
#24 0xb76197f0 in gst_element_set_state (element=0x9050b50, state=GST_STATE_PAUSED) at gstelement.c:2405
#25 0xb7f56b86 in ?? () from /usr/lib/librhythmbox-core.so.0
#26 0xb7f4646b in rb_player_open () from /usr/lib/librhythmbox-core.so.0
#27 0xb7eccb5a in ?? () from /usr/lib/librhythmbox-core.so.0
#28 0xb7eccce4 in ?? () from /usr/lib/librhythmbox-core.so.0
#29 0xb737fdef in g_thread_create_proxy (data=0x82db000) at /build/buildd/glib2.0-2.24.1/glib/gthread.c:1893
#30 0xb743896e in start_thread (arg=0xa91feb70) at pthread_create.c:300
#31 0xb7023a4e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

This particular crash happened when switching from an mp3 file to mms://straumr.nrk.no/nrk_radio_ndte_p1_h