I have an SIP account 12345@ekiga.net (fake number here) connected in empathy. From my SIP phone I call *67312345. telepathy-sofiasip crash with that backtrace:

#0  link_interface (type=157871720, interfaces=<value optimized out>, iface_quark=271, iface_impl=0x806ad80) at dbus-properties-mixin.c:356
	iface_info = (TpDBusPropertiesMixinIfaceInfo *) 0xb7b8be48
	prop_impl = (TpDBusPropertiesMixinPropImpl *) 0x806a900
	__PRETTY_FUNCTION__ = "link_interface"
#1  0xb7b489d9 in tp_dbus_properties_mixin_class_init (cls=<value optimized out>, offset=96) at dbus-properties-mixin.c:583
	iface_quark = 271
	other_impl = <value optimized out>
	q = <value optimized out>
	type = 157871720
	mixin = (TpDBusPropertiesMixinClass *) 0x9691268
	iface_impl = (TpDBusPropertiesMixinIfaceImpl *) 0x806ad80
	interfaces = (GType *) 0x96926c8
	__PRETTY_FUNCTION__ = "tp_dbus_properties_mixin_class_init"
#2  0x0805c1d9 in ?? ()
No symbol table info available.
#3  0xb7f5ac3c in g_type_class_ref () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#4  0xb7f4058e in g_object_new_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#5  0xb7f4094e in g_object_new () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#6  0x08053798 in ?? ()
No symbol table info available.
#7  0x08053aa2 in ?? ()
No symbol table info available.
#8  0x08057b5b in _tpsip_marshal_BOOLEAN__POINTER_POINTER ()
No symbol table info available.
#9  0xb7f39c4b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#10 0xb7f50095 in ?? () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#11 0xb7f5162b in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#12 0xb7f51c26 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#13 0x080577c6 in ?? ()
No symbol table info available.
#14 0x08057246 in tpsip_connection_sofia_callback ()
---Type <return> to continue, or q <return> to quit---
No symbol table info available.
#15 0xb7e7a678 in ?? () from /usr/lib/libsofia-sip-ua.so.0
No symbol table info available.
#16 0xb7eccaac in ?? () from /usr/lib/libsofia-sip-ua.so.0
No symbol table info available.
#17 0xb7f2bc82 in ?? () from /usr/lib/libsofia-sip-ua-glib.so.3
No symbol table info available.
#18 0xb7bc66f8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#19 0xb7bc9da3 in ?? () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#20 0xb7bca2c2 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#21 0xb7b64e83 in tp_run_connection_manager (prog_name=0x8064315 "telepathy-sofiasip", version=0x80648ff "0.5.11", 
    construct_cm=0x804fdc0 <tp_group_mixin_change_flags@plt+380>, argc=1, argv=0xbfdefa94) at run.c:261
	fatal_mask = <value optimized out>
	connection = <value optimized out>
#22 0x0804fd97 in ?? ()
No symbol table info available.
#23 0xb799b685 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#24 0x0804fc81 in ?? ()
No symbol table info available.