Occassionally the "All" screen starts displaying two rows of icons instead of the normal single row. Again, very random. To correct this, I open Options, Display, Home Screen Preferences, then Rest Setting and select Icon Arrangement. That fixes it immediately, but still not sure of the root cause.
I have worked this out on the bold 9900. You simply touch the screen to open up the menu. When it is opened, simply touch the menu header and drag it down to show the desired number of rows. One or two, or pull it down till they all go down to show no icons!