Google Cache All Over The Place

Anyone know whats going on with Google and there Cache of pages at the present time

My two highly ranked PR4 home page sites are a good example of this, one of them has its home page cached daily and was last cached today 20 June, the other one which actually ranks higher on Google was last Cached on 6 June.

Also we have links from other sites that are PR4 pages one click from the home page and they havent been cached since June 1 however this seems to be less of a problem as the home page on those sites is cached every two days or so.

Any ideas?

Thanks for your input

Btw what is an expires header (i havent changed anything)?

One site seems to get updated daily and obviously the other one hasnt been updated for two weeks

This is the one that hasnt been updated daily http://www.spanishhotproperties.com it may just be because this is a much bigger site etc

Again thanks for your input.

It might just be “one of those things”. I very much doubt that the published PR has any bearing whatsoever on caching rates (it doesn’t have very much effect on anything at all, to be honest). Does the homepage of one site get updated more often than the other? Have you set an “expires” header on one of them?

See http://www.mnot.net/cache_docs/#EXPIRES

One site seems to get updated daily and obviously the other one hasnt been updated for two weeks

Sorry, what I meant was - do you update the home page on one site more frequently than on the other?

This is the one that hasnt been updated daily http://www.spanishhotproperties.com it may just be because this is a much bigger site etc

That’s an entirely possible reason! If Google only pays each site a certain number of visits a day, and one site has a lot more to crawl than the other, it could well be that the homepage gets looked at less often.