When I come on line, I normally go to "posts since last visit". Sometimes, when I click on a thread and then hit the back arrow key, the index goes back to an earlier time when there were, say, only six posts. Then if I click on "index", and then "posts since last visit" again, it comes up to the current time with the correct number of threads shown, for example 17, or whatever. Why????? Admittedly not a big deal, but annoying. This is a G-5 imac using Safari browser that it came with. As I am on no other forums, can't judge this as abnormal to my machine or not.