Quite frequently, the 'back' button, (the little triangle in upper left corner) won't let me 'go back'. For instance, if I'm checking my email, and click on a link someone sent me, I can't go back to my inbox, I have to use 'History' to get back to my main inbox. It also happens when i'm on a website which has a link to another website. Is this normal? (Lion 10.7.2). It doesn't happen in windows (XP or 7). Also, is there a name for those 2 little triangles? Thanks.