Unexpected node type 711

I am trying to update a view, and I get the following error:

ERROR: expression_tree_walker: Unexpected node type 711

Version: PostgreSQL 7.3.2

The view is to replace an old view, but I get the same view
if I rename it and create a new view. The relevant portions
of the view that changed are listed below:

------------OLD VERSION---------------------
CREATE OR REPLACE VIEW XXXXXXXX
...
CASE WHEN sv.is_bit_field THEN sv.length
ELSE cdt.bit_length * COALESCE(sv.length, 1)
END AS bit_length,
...
--------END OLD VERSION---------------------

------------NEW VERSION---------------------
CREATE OR REPLACE VIEW XXXXXXXX
...
CASE WHEN sv.is_bit_field THEN COALESCE(sv.length, const.num_value, ev.value, evconst.num_value)
ELSE cdt.bit_length * COALESCE(sv.length, const.num_value, ev.value, evconst,num_value, 1)
END AS bit_length,
...
OUTER JOIN t_Constants const ON sv.fk_t_Constants = const.pk_t_Constants
OUTER JOIN t_Enum_Vars ev ON sv.fk_t_Enum_Vars = ev.pk_t_Enum_Vars
OUTER JOIN t_Constants evconst ON ev.fk_t_Constants = evconst.pk_t_Constants
--------END NEW VERSION---------------------

Any help on what went wrong? As far as I can tell, I'm not
doing anything here I haven't in a hundred other places.

--David