Comment 2 for bug 751230

StacktraceTop:
 currency_get_value (currency=0x0) at currency.c:75
 unit_convert_from (unit=0x8a97a00, x=0xbffcd614, z=0xbffc9730) at unit.c:141
 unit_category_convert (category=0x8b41620, x=0xbffcd614, x_units=0x8a97a00, z_units=0x8a97a60, z=0xbffcb6c4) at unit-category.c:100
 update_result_label (converter=0x8a49b38) at math-converter.c:72
 g_cclosure_marshal_VOID__VOID (closure=0x8bbbf00, return_value=0x0, n_param_values=1, param_values=0x8dab2a8, invocation_hint=0xbffcf6e0, marshal_data=0x0) at /build/buildd/glib2.0-2.28.5/./gobject/gmarshal.c:79