I just upgraded to Firefox 9 today, and I have always used Firefox 3.6, I've tried previous versions but all of them had this problem. The problem is with bookmark folders in my toolbar. For example, I have a folder with all my regularly visited sites (around 50) and when I open it and run the cursor up and down through the bookmarks, the blue highlight bar lags behind where the cursor is and it's quite bad. This happens in all folders. This doesn't happen with Safari or Chrome, both browsers are silky smooth when I move the cursor up and down in the same folder and the highlight bar never lags behind, it follows the cursor exactly, even when moving the cursor very fast. This didn't happen in Firefox 3.6 and it's odd that it would happen in all the newer versions. Does anyone know what is going on? I can't figure it out.