Drop in page indexing by google in this month

[pankajj]

Hi,
I saw a gradual drop in the number of pages indexed by google from 5500 to 4500 in past one month.
Has oneone else observed similar trend.
Do we know some logical aspects behind this..
Kindly suggest..

[tedster]

I just checked a few sites - no pattern here. Some are up and some down in googlebot spidering.

[StudioWorks]

The only pattern I currently see is the huge drop in serp's for some of my sites.