BUG #5041: Changing data_directory problem

The following bug has been logged online:

Bug reference: 5041
Logged by: Jonas
Email address: jonasdonovan(at)hotmail(dot)com
PostgreSQL version: 8.4
Operating system: Ubuntu 9.10
Description: Changing data_directory problem
Details:

After changing data_directory - in the same way as I did for postgres 8.3 -
postgres 8.4 gives me:

root(at)ip-10-224-94-129:/mnt/postgresql/8.4/main# sudo
/etc/init.d/postgresql-8.4 start
* Starting PostgreSQL 8.4 database server
Error: could not exec /usr/lib/postgresql/8.4/bin/pg_ctl
/usr/lib/postgresql/8.4/bin/pg_ctl start -D /mnt/postgresql/8.4
/main -l /var/log/postgresql/postgresql-8.4-main.log -s -o -c
config_file="/etc/postgresql/8.4/main/postgresql.conf" :