Backtrace from the crash log:

 #0  0xb760d37a in memcpy () from /lib/tls/i686/cmov/libc.so.6
 No symbol table info available.
 #1  0xb790d717 in IA__g_string_insert_len (string=0x8e2d8f0, pos=-1, 
     val=0x8d67560 "SPARCS", len=288428136) at gstring.c:479
 	offset = 4058464
 	precount = 6
 	__PRETTY_FUNCTION__ = "IA__g_string_insert_len"
 #2  0xb790d956 in IA__g_string_append_len (string=0x8e2d8f0, 
     val=0x8988868 "markup", len=6) at gstring.c:530
 	__PRETTY_FUNCTION__ = "IA__g_string_append_len"
 #3  0xb7a15ddc in text_handler (context=0x8f10dc0, text=0x8988868 "markup", 
     text_len=6, user_data=0x8e95680, error=0xbf9d5700) at pango-markup.c:430
 	end = <value optimized out>
 	range_end = <value optimized out>
 	uline_len = <value optimized out>
 	p = <value optimized out>
 	range_start = <value optimized out>
 	uline_index = <value optimized out>
 #4  0xb78f7acc in IA__g_markup_parse_context_parse (context=0x8f10dc0, 
     text=0x8ebcbd8 "<span weight='bold'>SPARCS</span> (15/40)", text_len=41, 
     error=0xbf9d57b4) at gmarkup.c:1479
 	tmp_error = (GError *) 0x0
 	unescaped = (GString *) 0x8d9ded0
 	first_invalid = (const gchar *) 0x8ebcc01 ""
 	__PRETTY_FUNCTION__ = "IA__g_markup_parse_context_parse"
 #5  0xb7a15964 in pango_parse_markup (
     markup_text=0x8ebcbd8 "<span weight='bold'>SPARCS</span> (15/40)", 
     length=41, accel_marker=0, attr_list=0xbf9d57b0, text=0xbf9d57b8, 
     accel_char=0x0, error=0xbf9d57b4) at pango-markup.c:637
 	context = (GMarkupParseContext *) 0x8f10dc0
 	needs_root = 1
 	tmp_list = <value optimized out>
 	p = <value optimized out>
 	end = <value optimized out>
 	__PRETTY_FUNCTION__ = "pango_parse_markup"
 #6  0xb7b6d558 in gtk_cell_renderer_text_set_property (object=0x8389948, 
     param_id=2, value=0xbf9d5868, pspec=0x83fa4e8)
     at gtkcellrenderertext.c:1022
 	str = (const gchar *) 0x8988868 "markup"
 	text = (gchar *) 0x0
 	error = (GError *) 0x0
 	attrs = (PangoAttrList *) 0x0
 	celltext = <value optimized out>
 	priv = (GtkCellRendererTextPrivate *) 0x83899b0
 #7  0xb796bb8a in IA__g_object_set_property (object=0x8389948, 
     property_name=0x82e9560 "markup", value=0xbf9d58c8) at gobject.c:697
 	nqueue = (GObjectNotifyQueue *) 0x8aa6c50
 	pspec = (GParamSpec *) 0x83fa4e8
 	__PRETTY_FUNCTION__ = "IA__g_object_set_property"
 #8  0xb7d30bcc in IA__gtk_tree_view_column_cell_set_cell_data (
     tree_column=0x83fd060, tree_model=0x8278ad8, iter=0xbf9d59e4, 
     is_expander=1, is_expanded=1) at gtktreeviewcolumn.c:2519
 	info = (GtkTreeViewColumnCellInfo *) 0x8402438
 	cell = (GObject *) 0x8389948
 	list = (GSList *) 0x83f85c8
 	value = {g_type = 64, data = {{v_int = 148440976, v_uint = 148440976, 
       v_long = 148440976, v_ulong = 148440976, v_int64 = 148440976, 
       v_uint64 = 148440976, v_float = 1.30619904e-33, 
       v_double = 7.3339586676744978e-316, v_pointer = 0x8d90790}, {v_int = 0, 
       v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, 
       v_float = 0, v_double = 0, v_pointer = 0x0}}}
 	cell_list = (GList *) 0x839ed70
 	__PRETTY_FUNCTION__ = "IA__gtk_tree_view_column_cell_set_cell_data"
 #9  0xb7d154bf in validate_row (tree_view=0x83fb010, tree=0x82da408, 
     node=0x8727520, iter=0xbf9d59e4, path=0x8c557f0) at gtktreeview.c:5523
 	tmp_width = 136809176
 	tmp_height = 1
 	column = (GtkTreeViewColumn *) 0x83fd060
 	list = (GList *) 0x839ed00
 	first_column = (GList *) 0x839ed00
 	last_column = (GList *) 0x83a02b0
 	height = 0
 	horizontal_separator = 2
 	vertical_separator = 2
 	focus_line_width = 1
 	depth = 1
 	retval = 0
 	is_separator = 0
 	focus_pad = 1
 	grid_line_width = 1
 #10 0xb7d198e8 in do_validate_rows (tree_view=0x83fb010, queue_resize=1)
     at gtktreeview.c:6102
 	tree = <value optimized out>
 	node = <value optimized out>
 	validated_area = 0
 	retval = <value optimized out>
 	path = (GtkTreePath *) 0x8c557f0
 	iter = {stamp = -744585524, user_data = 0x86a3f18, user_data2 = 0x0, 
   user_data3 = 0x0}
 	i = 0
 	prev_height = -1
 	fixed_height = 1
 	__PRETTY_FUNCTION__ = "do_validate_rows"
 #11 0xb7d19c57 in validate_rows_handler (tree_view=0x83fb010)
     at gtktreeview.c:6174
 	retval = <value optimized out>
 #12 0xb78efaa1 in g_idle_dispatch (source=0x8e6fa80, callback=0x8988868, 
     user_data=0x83fb010) at gmain.c:3926
 No locals.
 #13 0xb78f1802 in IA__g_main_context_dispatch (context=0x8183d18)
     at gmain.c:2045
 No locals.
 #14 0xb78f47df in g_main_context_iterate (context=0x8183d18, block=1, 
     dispatch=1, self=0x8165ba8) at gmain.c:2677
 	got_ownership = <value optimized out>
 	max_priority = 125
 	timeout = 0
 	some_ready = 1
 	nfds = <value optimized out>
 	allocated_nfds = <value optimized out>
 	fds = (GPollFD *) 0x87f4378
 	__PRETTY_FUNCTION__ = "g_main_context_iterate"
 #15 0xb78f4b89 in IA__g_main_loop_run (loop=0x84606a0) at gmain.c:2881
 	got_ownership = -1215757344
 	self = (GThread *) 0x8165ba8
 	__PRETTY_FUNCTION__ = "IA__g_main_loop_run"
 #16 0xb7c26574 in IA__gtk_main () at gtkmain.c:1024
 	tmp_list = (GList *) 0x8167138
 	functions = (GList *) 0x0
 	init = (GtkInitFunction *) 0x0
 	loop = (GMainLoop *) 0x84606a0
 #17 0x0810fd0c in main ()

That looks like a pango or GTK issue rather than a gaim one