Very strange, I work with a guy who has two websites: http://www.fire-risk-assessment-uk.co.uk http://www.asbestos-surveys-uk.co.uk Both sites are in the Google index and the rest of their pages are cached. Only the homepages arent?? has anyone seen this before - got to be some technical issue. Why would Google do such a thing? No meta no-cache or robot txt. Strange
robots.txt is the prime source for such error. I have seen in some case google deindexes the whole site but only the front page is more often an internal error. Did you see if there is an error / warning in google webmaster tools console?
you can submit it in all major search engine and do social Bookmarking in Digg and sumble etc I am 100% sure it will cache soon