I got a new computer this week and downloaded/installed Firefox, then imported my old bookmarks. Now I'm having a problem I didn't have before. First the bookmarks got odd: before, when I moved to look at a new folder the old one disappeared. But now, the folders get stuck and their rows of bookmarks stay open in the background even when I move to look at a new folder, and the blue colour that shows which folder or link I've currently selected can also be slow so that for a while it looks like it's split in two before it fills the whole of the folder/link that my mouse is pointing at. When I right-click to save an image for example, the right-click list of options stays visible even after another screen has opened so I can name the image to be saved; sometimes the right-click list is stuck on the screen for seconds even if I don't choose an option and just click the background to get away from it. This is not normal: all these things used to disappear from the screen instantly when they were no longed used or I clicked something else.

This problem seems to be getting more noticeable. At first only the bookmarks seemed slow to disappear when I was browsing folders. Then the right-click list started getting stuck in the background when I saved images. Now when I go through bookmarks everything stays onscreen no matter how many new folders I move to; they're stacked on top of each other.