Since updating to FF 4 on Mac running Snow Leopard, I've been having problems with hyperlinks. When visiting most website (I first noticed it on Google), hyperlinks are no longer highlighted blue. They highlighting doesn't change on mouse over as it normally has in the past. The cursor does not change shape on hyperlink mouse over. Despite these problems, I am still able to click on all available hyperlinks. However, after clicking on a hyperlink displaying the above problems, the previous page is no longer available in the history (which means that the 'back' button is no longer available for use).