PR6 to PR4 why this drop suddenly

Can someone explain me what went wrong?

[ritesh]

Hi Guys,
I have been working on my site optimization for the past one and a half year and achieved top positions for a few keywords at Google. I had the PR6 and now suddenly the PR has droped to 4. I cannot understand this as I have practically not changed anything in the past 4 weeks that possibly can lead to negative ranking (As far as I know). As a result of this I have also lost a top 10 position on many keywords. Can someone explain me what went wrong?

Regards,
Ritesh

[aek]

Page rank is based on the quality of the incoming links to your website. It sounds to me that you either lost some incoming links or the incoming links you have dropped in Page rank, therefore your own page rank dropped.

Concentrate on getting more incoming links and your page rank will improve again.