PFI / free inktomi - can you tell from the bot datails in server logs?

can you tell PFI inktomi from free inktomi from the robot request details

[sabai]

I have had this site up for 10 weeks, did a few PFI pages in inktomi to get MSN results. I had always seen the following IP/hostname for my PFI pages when slurp comes around to collect the pages.

IP: 66.196.73.51
HOST: j6002.inktomisearch.com

I have done something like www.SITE.com?engine=inktomi so that I can see clearly a request for a PFI page, from either slurp or a web browser.

I noticed a new IP/host for slurp, in addition to my existing pages, I see slurp requesting my index page as www.SITE.com/ - something I have never paid for. Slurp comes to pick this page up quite regularly, but at a different time to my PFI pages.

New one...

IP: 66.196.72.66
HOST: j3156.inktomisearch.com

I have seen no web browser requests with referer either msn.com or hotbot.com for the index page in the www.SITE.com/ form.

I am thinking that perhaps inktomi has picked up a link to my site and I am getting a free listing for the page, but it is not listed yet. Does anybody know if I am correct in this assumption? Does anybody do PFI and have free pages?

thanks.

[edit]edited to say that the request header details and the useragent are identical[/edit]