But what is most interesting, by tracking the exact minute when they swich off or switch on, i could spot 5-10 Aol visitors all from Reston Virginia during one minute, after their visit... All google traffic vanishes or appears again... Anyways seems like those are about all Aol visitors i ever get What a mystery!!

You must have massive amounts of spare time?

If working on SEO is spare time for you, then yes!!

Did you check the data centers?
Might just be that you hit a different data center each time things seem to change. I have had this kind of thing happen many times during the same day/week/hour.

In the morning the site was indexed in the afternoon it was not.
Next morning it was index and in the afternoon it was gone again.
I was getting different data center results each time.

This is why i asked if you have to much time to spend on this, it takes time for things to flow to all data centers, relax and things will work out if the site has value to the users.

My site is 2 years old it has been stable all the time until last month. I am talking about tracking visitors as well. All data centers throw my SERPs to the outbounds, then return first page positions ))) Now it has been stable "ON" for 3 days ))

The site has been well indexed since the beginning. Now every 3 -4 days. With this last month up and down in SERps It meens 500 Google daily visitors become 50

I noticed that too google and other also behaving very wierd lately...((
This sudden rankings jumping are crazy .
Why is this happening???
Maybe they promote some sites for $ then when the say - now see your site is 1st after some days they switch them off and return all to normal .

I guess the google results are from different data center.
Perhaps the main google data centers are in maintenance..
Who knows???

I have noticed the same thing. At certain times of the day my site is on page one of Google Serp for a paticular keyword. At other times of the day it is on page 4 for the same key word. This seems to happen everyday. In trying to research this I saw on other threads people making fun of people for asking the question. I think it is a very legitimate question since it is affecting the traffic and thus the business your site is doing. Also it seemed 90% of the sites on page one stayed the same it was only mine a couple of others that would appear and then disappear from page one. So if I am doing something to cause this I sure wished I knew what it was if it's just Google then I thing in brings into question their credibility to produce such inconsistent results.