can't create type lo (BLOB)

Hi @ all, thats my problem :

CIMSOFT=# CREATE TYPE lo (internallength=4, externallength=10, input=int4in,
output=int4out, default='', passedbyvalue);

ERROR: TypeCreate: function int4out(lo) does not exist
ERROR: TypeCreate: function int4out(lo) does not exist

CIMSOFT=# SELECT version();
version

----------------------------------------------------------------------------
-----------
PostgreSQL 7.3 on i686-pc-cygwin, compiled by GCC gcc (GCC) 3.2 20020927
(prerelease)
(1 row)

Why this? With PostrgreSql 7.2 this works well.

Thanks for help