First step: Please go to http://www.finanz-links.de/test.htm You see "Page 1". (There are 2 other pages: "Page 2", "Page 3" in this test set) If you click through the pages without loading the frame, all works fine: all 3 Google Adsense ads are shown. Second step: To reproduce the error: Go to "Page 1". Click on frame and load it. There are now 3 windows. Then go from "Page 1" to "Page 2" by clicking on the link "Go to page 2" provided on "Page 1". Two Adsense ads dissapeared and only 1 ad is shown. Then go from "Page 2" to "Page 3" by clicking on the link "Go to page 3" provided on "Page 2". All Adsense ad dissapeared and none ads are shown. This problem only occurs in Firefox (not only Nightly). This problem doesn`t occur in IE or Chrome. Regards, Lothar