There are certain links that don't work after upgrading to FF4 but they still work just fine in IE8. I've only noticed them on one site so far. It seems all the other links on the following site work except the ones at the bottom of the articles. Both the numbers for the other pages and the one that says Next. It seems to be any article with more than one page and not just the one that I linked for reference. I tried running FF in safemode but it didn't make a difference.