how find hidden tempos

Make sure under the view menu, Show invisible is checked. This will allow you to see invisible items in a light gray color. These are probably used to simulate rit. and accel. You can select the section of music where these invisible tempos are (make sure not to select tempos you do not want to delete) and right click a tempo and use Select>All similar elements in range selection and press delete to get rid of all of them at once. If you happen to accidentally select a tempo you don't want, you can unselect it using ctrl+left click.