I have a site which had experienced a change in IP address from shared IP to static IP over 2 months ago. The physical server and nameservers for the domain remained the same. The change was only in shared IP to static IP. I am seeing a strange behavior on the spidering pattern of googlebot with its different IPs. The bot with IPs 6x.xxx.xxx.xxx spiders the site correctly at the current static IP address. However the bot with IPs 216.xxx.xxx.xxx is spidering the site at old IP address which was a shared IP(so it is accessing the main cobalt raq server page and getting a bunch of File Not Found pages). The site in question was a year old and ever since the IP change 2 months ago on May 4th, one month google indexed the main cobalt raq page as our home page with high PR and in this month update it removed the entire site. Not sure what it is going to do next month!. My question would be why the bots are so confused about a mere small change in IP address of a domain from shared to static IP?. And what could I possibly do to correct this behavior and see my site is indexed back correctly!