index corruption and having to reindex

select count(*) FROM items_2004_07_29 as items WHERE true AND index @@ to_tsquery('default', '( audiovox)') ;
count
-------
4
(1 row)

aers=# reindex index idx_title_2004_07_29;
REINDEX
aers=# select count(*) FROM items_2004_07_29 as items WHERE true AND index @@ to_tsquery('default', '( audiovox)') ;
count
-------
2342
(1 row)

Here are 2 searches using a gist index, the first one has a gist index which is not properly created but does not though an error in creation. After doing a few searches I noticed the numbers were way off so I reindexed. The problem was fixed and the search works properly.

Is there a problem with indexing? Do you know of this problem?
Is there a way to fix it?

Thank you,

Aaron