Site In and Out of serps

[Fish_Texas]

What would cause a site to be dropped from the serps one day and show up again a few days later? This has happened 3 to 4 times over the last 2 months. It's a complete drop in 1 day, not gradual, then a few days to a week later, it all reappears in 1 day.
Thanks for any input.
Fish Texas

[tedster]

Do you mean that the site: operator show no pages indexed some of the time, or that a high ranking is there and then is gone?

[Fish_Texas]

Thanks Tedster,
The cached pages in the index stay the same and a few pages still show as well as index page in serps...traffic drops 99% then returns days later back to normal. Even with exact title search, pages are not there.

Could the site be borderline for a penalty?
Would higher PR backlinks do the trick?
Or is it a glitch with Google?
I read the thread on latest yo-yo effect but couldn't find my exact situation.
Thoughts?
Fish Texas

[edited by: Fish_Texas at 8:15 pm (utc) on Sep. 28, 2008]

[tedster]

It sounds like the Yo-Yo syndrome. What do you see as different in your situation?