Yes, I know this question has been asked many times. our site was instantly indexed with just one link and that lasted 1 week. Then all of a sudden it was not indexed at all. Since that happened I went out and got 4 more links. 1 PR 5 even. It is still not being indexed. No, it is not too many links in a short period. IT was very natural linking. What is the normal reporting time for being indexed? What is going on lately I haven't started a new site for a year now and am used to the old days when it would get indexed with no problems. Is it one week for a new site then a revisit after one month?
Sounds like what is known as the "google honeymoon".. new site ranks high for a few days, then drops down to more normal levels. That's not to say your current disappearance is normal... but you may find it will take a while to climb back up after you get indexed (again). But still... check your site using google's webmaster tools just to make sure everything is ok. I've noticed google jumping around a lot right now... been waiting 10 days for a home page crawl of well-ranked content site, which is an unusually long time. All of the above (backlinks, content, etc) matters, as well as a little patience.
if it's brandnew site (site that got less than 1 year old) it would be easy to happen. so just give them some more time and build more links especially from PR sites may help. It will take time just be patience.
when you say "gone" do you mean gone as in the site: search? even so wouldnt worry about it, Google has doen this with almost every new page or Blog we've launched for about 6 weeks now, after a day or two it's indexed, showing up in searches, then disappears again for a week or so, then returns again. it seems to be a charcteristic of their indexing process now. theres' also a timescale with new pages where they show in the site search, but checking the cache just gives a URL and error, while they assess and categorise it maybe? i'll bet it will be back
New sites get indexed and rank high in search results but only for few days. It is because google love new content. If you want to get well indexed and well ranked, then build lots of Backlinks