It appears that databases are to be upgraded!
Here's what I did to make sql-ledger work again:
Before upgrading postgres, I had a dump of all databases (pg_dump -c -F p -U postgres <database>).
Stop postgres
yum install as above
UPGRADE TO 8:
=============
mv /var/lib/pgsql/data /var/lib/pgsql/data7.4
su postgres
initdb -D /var/lib/pgsql/data
exit
/etc/init.d/postgresql start
mv /home/e-smith/files/ibays/../databases/pg_*.* /var/lib/pgsql/backups
su postgres
cd /var/lib/pgsql/data
createuser -d -P sql-ledger
createuser -d -P ledgersmb
createdb ledgersmb
createdb <databases>
createlang plpgsql template1
exit
psql <databases> < backups/pg_<databases>
Sql-ledger is now working!
Ouch!!