I have a lot of visitors that bookmark my site... However, over the past few months I have added and delete pages... Now just wondering if someone that have bookmarked a particular page that had adsense ads (but that pages has since been deleted) and but the visitor click on the ad (from a cached page) ... will adsense suspect that as a defraud click... thanks...
No. Google can tell which page the click comes from (the JavaScript code grabs the info) and it can obviously tell that the page came from its own cache. Even sites whose pages are still around get the occasional click from cached versions of those pages. I hope, though, that you're redirecting your old pages to the new pages. It's never good for visitors to come across a "404 Not Found" error when they click a link. Never remove pages, just redirect them.
When I delete a page I delete all reference to that url in all my links... my issue was that most of my visitors bookmark my site... and would still have access to some old pages.... I think I will have to add a post to ask all visitor to update their bookmark when next they visit... as I think I got a click on a page that was deleted about a year ago... My goodness.... has it been a year since I started with adsense... where did that time go... I know sitting in front of my computer updating Elvis on a daily bases... Got to get a life...
But that's not good enough. Other sites outside of your control may be linking to those pages. It's always better to configure your web server to redirect the old page to a new page. Or even change the old page to a "This content has been removed, but you should consider these other pages instead..." Make it easy for visitors to stay on your site once they get there, even if it's via an old link.