Error: No one parent tuple was found

Hi!

This is my problem:

uname -a
Linux mail 2.4.18-3 #1 Thu Apr 18 07:37:53 EDT 2002 i686 unknown

xxx=# select version();
version
-------------------------------------------------------------
PostgreSQL 7.2.1 on i686-pc-linux-gnu, compiled by GCC 2.96
(1 row)

psql -d colabo -c "vacuum full verbose analyze"

NOTICE: --Relation pg_largeobject--
NOTICE: Pages 84730: Changed 68898, reaped 83003, Empty 0, New 0; Tup
948705: Vac 46341, Keep/VTL 0/0, UnUsed 533451, MinLen 44, MaxLen 2092;
Re-using: Free/Avail. Space 52105268/52023388; EndEmpty/Avail. Pages
0/78465.
CPU 3.56s/1.98u sec elapsed 60.15 sec.
NOTICE: Index pg_largeobject_loid_pn_index: Pages 5947; Tuples 948705:
Deleted 3.
CPU 0.17s/0.79u sec elapsed 9.57 sec.
ERROR: No one parent tuple was found

In a mail of the 12 of August Tom Lane say that this problem is solved in
version 7.3 but so far I cannot make the update.
In that same mail, Tom proposes to do

psql -d colabo -c "select * from pg_largeobject for update;"

But...

"Apr 28 11:16:45 mail kernel: Out of Memory: Killed process 12168 (psql)."

So wath can i do?

Thanks!!!

Sergio