As Mozilla Firefox 2.0 is quickly approaching I believe that this web browser suffers from some severe problems which do not get enough attention from Mozilla Corporation developers. I would not like to make unfounded statements so I will enumerate these bugs right now:
1) All gecko/XUL based products suffer from slow interface rendering and high CPU usage in basic UI operations like menu showing
2) You cannot scroll or do anything else in the current window of Firefox browser if the latter is rendering a page in a new window or Tab
3) Mozilla Firefox has no protection against crashes so upon restart you will lose all stored cache and all open windows
4) Mozilla Firefox has no option to disable iframes support - an option which has been implemented in Opera and IE seven years ago
5) Mozilla Firefox still has no option to view an image withing the current page by right clicking it and pressing "Show the image"
6) Firefox still has no simple per-site policy of setting browsing settings like cookies/Javascript/images/styles/cache/etc.