Problem executing user function (on Solaris)

Hi,

I am using plpgsql to write user function and type.
I am facing problem while executing the function.

psql=# select * from GSS_FUNC_REQ_CDR_COUNT();
ERROR: parser: parse error at or near "("

psql=# SELECT GSS_FUNC_REQ_CDR_COUNT();
NOTICE: plpgsql: ERROR during compile of gss_func_req_cdr_count near
line 0
ERROR: fmgr_info: function 0: cache lookup failed

psql=# \df GSS_FUNC_REQ_CDR_COUNT
List of functions
Result data type | Name | Argument data types
------------------+------------------------+---------------------
gss_counter_type | gss_func_req_cdr_count |

I am using PostgreSQL 7.4.3 on Solaris 5.8

BUT,If I try the same stuff on my Linux box(Debian 2.4.4-pre3+,i686),
things are working fine.
psql=# select * from GSS_FUNC_REQ_CDR_COUNT();
store_drt | acked_drt | store_cdr | acked_cdr
-----------+-----------+-----------+-----------
400 | 12 | 400 | 12

Can anybody suggest, How to solve this problem?

Thanks,
Rajan Bhide