BUG #3876: Problems migrating databases

The following bug has been logged online:

Bug reference:      3876
Logged by:          Ruben Camargo Gomez
Email address:      rubencamargogomez@hotmail.com
PostgreSQL version: 8.1
Operating system:   Linux Red Hat Enterprice 5
Description:        Problems migrating databases
Details:

Hi, frist of all thanks in advance.

I have a postgres service running in a red hat enterpise 4; this server is
8.0.13 version and is
working fine.

Now I whant to migrate my database to my new server running red hat
enterprise 5; this operating system comes with a postgres 8.1.9 pre
instaled; I did restore a backup of my database into this version but some
of my triggers and stored procedures do not work

I had this error from my log file:
ERRORROR:  missing FROM-clause entry for table "tbldishot"

And this other one:

CONTEXT:  SQL statement "update tblalohot set  alohot_con =
coalesce(alohot_con,0)+8 where tbldishot.dishot_cod = tblalohot.dishot_cod
and tbldishot.establ_cod = 8699 and tbldishot.tiphah_cod=7 and
tblalohot.establ_cod = 7713 and tbldishot.dishot_fec >= '2007-10-23' and
tbldishot.dishot_fec < '2007-10-24'"
        PL/pgSQL function "fun_reg_dis" line 34 at

execute statement
        SQL statement "SELECT  fun_reg_dis(cast( $1  as integer),cast( $2
as integer),cast( $3  as integer),cast( $4  as integer),cast( $5  as
integer), $6 , $7 )"

I really whant to know if I can do any thing to make my database work well
in my new server or if I have to install in this server my old postgres
version