The fact that your indexes are bloated but your table is not makes me
wonder if you're not running a really old version of pgsql that had
problems with monotonically increasing indexes bloating over time and
requiring reindexing.
That problem has been (for the most part) solved by some hacking Tom
Lane did some time back.
What version pgsql is this? If it's pre 8.0 it might be worth looking
into migrating for performance and maintenance reasons.