can't update bytea field with function

[scott johnston]

i have a stored procedure that goes

Create function myfunction(bytea)
returns void
as
'update tbl_entity SET Right_Thumb = $1;' language sql

the problem is that if i change the stored procedure code to say
update a varchar (ie of a different column) the stored procedure works
fine. but when i throw a bytea into the procedure i get an error
"column XXX is of type byte but expresion is of thype integer"

i can assure you that the colun i am trying to update is the correct
data type because i have a insert function that inserts blobs into the
column just fine. Is this a glitch in postgresql.

Can anybody help?