Storing null bytes in bytea

Hi all,

I was going to post this on the pgsql-php list but I think the issue is 
more on the PostgreSQL side of things.

I'm using PHP 5.2.9 connected to a PostgreSQL 8.3.7 server running on 
Solaris 10 to try to store the session data for an application using a 
custom session handler class.  The session data (objects/class instances 
etc) is serialized into raw bytes in PHP and contains a few nul/zero 
bytes (which are meaningful to PHP when it comes to deserializing the data.)

Because of the nul bytes, I've set the session_data column to be a bytea 
column in my database table.  However I cannot get PostgreSQL to read 
past the first nul byte on an insert, so the unserialize call fails when 
it reads it back out the database and the remaining data is omitted.

An example of such query is this:

INSERT INTO system.session (user_id, session_key, session_name, 
client_browser, date_created, date_expires, ip_address, session_data) 
VALUES (NULL, '4pc4sjciahoc4fuk1bt4kohe91'::character varying(32), 
'AppName'::character varying(50), 'Mozilla/5.0 (Windows; U; Windows NT 
6.0; en-GB; rv:1.9.0.9) Gecko/2009040821 Firefox/3.0.9 (.NET CLR 
3.5.30729)'::character varying(200), 
public.get_pg_timestamp(1240853862::integer), 
public.get_pg_timestamp(1240854162::integer), '192.168.0.8'::inet, 
E'IsLoggedIn|b:1;CurrentUser|O:17:"Class_SystemUser":4:{s:26:"\\000Class_SystemUser}'::bytea);

All other columns are fine, but when it comes to the session_data 
column, all I end up with is 
'IsLoggedIn|b:1;CurrentUser|O:17:"Class_SystemUser":4:{s:26:"'.  
Everything past the first "\\0000" byte sequence is ignored.

I've tried this with and without the 'E' at the beginning of the value 
string.

Any pointers as to what I'm doing wrong?

Thanks,
Andy