Does cached title indicate a reindex in Google?

[crickeys]

I was wondering if the cache is really an indication of how google is currently viewing your website internally, and I get a huntch that it isn't.

My SERPS has gone up about 30 positions after making some changes to my homepage and yet the original title and cache from a week ago seem to be listed on Google.

Is it likely that they have an updated version of my page, but the cache is delayed? If so, how can I tell if changes in my serps are because of google reindexing or just various other reasons?

Love to here your thoughts.

- Brian