Bungee Jumping results in Y! Natural Search

Yahoo natural search results random

[FlapJack]

I have observed for my keyword set, that natural search results on Yahoo are very odd. My initial search showed my site at number 3. I refresh and I give up looking for my site in the results after 100, A few more refreshes and I am back up at 3. Well I think I must be hitting different data centers. So I start pinging search.yahoo.com ( I am not sure if that is an effective test) and see the same IP. I wait a week test again exact same issue still continues.

Has anyone else seen this effect? ideas, concerns?

[seochristine]

Hi FlapJack
It is quite evident that there is some sort of update going on at Y!. Even I am observing sudden changes in SERP'S. My site used to rank top for most of my targeted keywords, a few days back and suddenly it has fallen back to the second page.
Even I pinged to check out the IP and it showed two different IP's.
Another impoprtant observation is that my site still at the top at [uk.yahoo.com...]