Actually, this is for a hotbot search, so I don't know if they tweak their rankings at all.
But I've dropped in a few keyword phrases from 4 or 5 to 6 or 7 on several keywords. There's a competitor of mine that I hadn't noticed in the top 5, but the date on their site is from last year, so they could've been there before.
Can anyone recommend a good read for inktomi SEO? I've read mostly about google so far.
Should I have separate pages optomized for each engine?
Neither me, nor my competitors have much in the way of inbound links, although I've been making decent progress lately.
You may be seeing the recent return of previously dropped PFI pages. Mine are back and I'm sure my competitors are wondering the same thing...
I personally would avoid building separate doorway pages aimed at specific SEs. With some exceptions - like post-florida google for certain terms - on-page optimization tends to be relatively consistent across many of them.
Keep working on the inbound links and take a look at the pages that recently overtook yours and do some tweaking.