message contents do not agree with length in message type "T"

Hello,

I'm using the libpq interface to PostgreSQL (8.3.0) in one of our apps, and
I'm having a sporadic issue with receiving the error message:

--snip--

message contents do not agree with length in message type "T" server sent
data ("D" message) without prior row description ("T" message)

--snip-

It doesn't happen all the time, and doesn't always happen on the same query.

--snip-

2008-03-10 22:09:29 [31010] - csql::query(): PGRES_FATAL_ERROR (message
contents do not agree with length in message type "T" server sent data ("D"
message) without prior row description ("T" message)) query='select
fc_system_end_call(1867,6)'

2008-03-10 21:39:38 [30262] - csql::query(): PGRES_FATAL_ERROR (message
contents do not agree with length in message type "T" server sent data ("D"
message) without prior row description ("T" message)

) query='insert into system_stats (type,subject,stat_value,stat_data) values
(501,0,9.027189,'')'

--snip-

In the first example, fc_system_end_call() is a plpgsql function

Schema | Name | Result data type | Argument data types

--------+--------------------+------------------+---------------------------
--------

public | fc_system_end_call | integer | _call_id integer, _status
integer

in the second example, system_stats is a table like:

Table "public.system_stats"

Column | Type |
Modifiers

------------+-----------------------------+---------------------------------
--------------------------

id | bigint | not null default
nextval('system_stats_id_seq'::regclass)

date | timestamp without time zone | not null default now()

type | smallint | not null

subject | bigint | not null default 0

stat_value | double precision | not null default 0

stat_data | text | not null default ''::text

Indexes:

"system_stats_id_key" UNIQUE, btree (id)

Foreign-key constraints:

"system_stats_type_fkey" FOREIGN KEY (type) REFERENCES
system_stat_types(id) ON UPDATE CASCADE ON DELETE RESTRICT

--snip-

Does anybody have any idea what this message means, and could be the issue
with what I'm doing?

I'm also sporatically getting these messages, and I'm not sure if they're
related or not?

--snip-

message type 0x54 arrived from server while idle

message type 0x44 arrived from server while idle

message type 0x43 arrived from server while idle

message type 0x5a arrived from server while idle

--snip--

Thanks for your time,

Mike