same situation here. I have asked them regarding this issue but I haven't received any replies. then last week i got an email from them, adsense-adclicks@..... stated "It has come to our attention that invalid clicks have been generated on the Google ads on your site(s)." I, once again, explained the situation above and asked them to give a detailed information on this "invalid clicks" issue. I haven't received any replies from them. note: I'm not baned, and I never click my own ads or asked someone to click them.
U'll get another Canned reply from them explaining that due to protection of their alogorithm they cant tell you details of invalid clicks but will look forward to work with you
Invalid clicks is probably from someone else clicking on your ads several times in a few seconds (using back button or something?). I have seen mine with 6 clicks but zero income from this one unpopular page. I'm quite sure the 6 clicks were done within a short period of times between each other. Google system can see it, so they can call it invalid.