QUOTE(Robsta @ Oct 29 2007, 04:35 PM)

There are quite a few servers, each potentially having slighty different results based on the search traffic that goes through them (apprently). Don't get obsessive about Google page rank, it's a figure that means very little in real terms.
I've got to disagree with you on this Rob. PageRank is a score that represents how Google view the quality of your website content. The actual mathematics behind it is very complex. In general, how your page ranks for a particular term is determined by the relevance of your site to that term, the number of links to your site that feature keywords that are relevant to the search term, and your PageRank. Let's face it, if Google think very little of your site's content, they are hardly going to rank your site highly for a competitive word or phrase.
As rob said, different servers may register different PageRanks for your site. I'm not sure if this is because your site may be more relevant to certain geographic regions (where the servers are located), or if it just takes time for the servers to synchronize the data.
Google have changed their PageRank algorithm numerous times recently. Many people are outraged as their website that once ranked no.1 is now on page 3! Some websites will allow you to check the PageRank of your website on many different Google servers. If they all show PR1, that's your new PageRank. As I said, it may have decreased due to an algorithm update. Alternatively, you may have lost some links from high PR and relevant websites. It may just take time to get to where you were.