Seo question about long tail keywords

[nest28]

Last night while checking google analytics, I saw that half the people that came to my site from longtail keywords left within a few seconds, so I copy and pasted the exact phrase into google to see what the problem was. Come to find out the landing page doesn't match what they are searching for. Let me explain, when my site appears on google a snippet of the correct article appears but when you click on my site instead of leading to that article the visitor wants, it leads to my home page. Is this normal, is there a way I can make it so my visitors land on the article the best answered their search phrase. I make most of my adsense money from long tail so if this problem can be solve I think more money can be made.

P.S.

[mosthost]

Could it be related to Google Instant? Perhaps people are clicking on results before they would normally even finish typing their query.