Upgrading PostgreSQL 7.1.3

Hi:

I'm planning to migrate a postgres database version 7.1.3 to a newer
version. There are some tables with up to 5 million records and I'm
begining to suffer from data corruption in indexes and tables. I did
some hardware checkings and everything seems ok. The last move, as
someone suggested in this list would be to upgrade postgres version.

What is the most advisable version I should upgrade to? My top goal is
reliability. Do I have to install/reinstall or upgrade? Do I need to be
concerned of any special feature when dumping/restoring data? Is there
any good doc about this?

Thanks in advance for your vaulable help.
Ruben.