I've experienced this with my surfing site. It's been going from 1 - 10 very annoying, even though its still on the first page for many useful keywords its hurting my products (affiliates) cheque.
Page 84! Woot (shrugs) update hit refresh back to 78 again wtf. update: more oddities. For my main keyphrase which is stuck on page 84 again (shrugs) it is showing a page from a couple of days ago in terms of page titles and meta des) yet if you Google arcades247 it shows the most uptodate title and meta des?
Update: page 82 lol, old page titles and meta des. Update: Vanished can't find. Update: Top page 82 grr Update: Vanished again 23.01BST
Fixed CMS issues affecting site, changed links from php mcid links to html links, fixed dupe meta des issues according to GWT. Update: page 7.
From what I've seen its usually either a new site or site with content that varies a lot but yours looks like its probably static. Have you checked the traffic to see if the rank vaires with the volume coming through?
The exact same thing has been happening to a good half of the sites I'm manging (over a few dozens) since june Some have been bouncing between page 1 and 2 and some can go as far down as page 5-7 at different times of day. I believe this is the Yo Yo effect people were discussing on seroundtable not long ago (seroundtable.com/archives/017705.html and seroundtable.com/archives/017817.html)
I went from getting a bunch of google hits a day to barely 1 google hit a day during the past month or so.. as of this morning, it appears back in action.. a bunch of hits every hour now from Google. Maybe they've corrected whatever they broke
I don't know what's going on then. I had the same problem, but it was only for a few weeks. It should settle out after that.
This search engine is churning like a mofo. Stuck at the back again for half a day, then back to page 2 or something then back to end again, what the hell is going on. Borderline glitching also as a couple of days ago I had a memory error and the site was down for about 1 day, this error was then shown in the serps, but I fixed it, and the fix was then shown, but a day later it reverted back to showing the error page with an old page title - hell idk what Google is doing. Right now im on page 80 for my main keyphrase.
We have actually typed our keyword in google, and I could see that our site was 3rd or 4th down on my keyword, then hit refresh on my on my google tool bar and my site disappeared! Very Weired! Its like seeing a ufo..LOL.. We have a theory that google is working on a new algorithm that takes into account your previously searched keywords.. However, this is just a theory..