I have recently come across a problem: I have a page which is cached by Google (double checked). It has not much text but still it is more or less unique. The page can't be found in google even with "text from the page" site:site.com. What does it mean?
It is a bad thing, means that the page or even worse the site got sanboxed, and it will take a while until you will see it live again, i believe that first you need to correct the problem and after that submit it for review.
Is it a new page? Did it just get cached within the last week? It can take a while especially if the website is new. New = no trust yet.
I have had this before, if you havent done anything dodgy then it has just temporarily dropped out of the index. Nothing to worry about